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Everyone's guide to using the ST 




A Data Becker Book 






























































The Atarr ST 
for Beginners 


Ranier Liters • Michael Stein 



A Data Becker Book 


Published by 

Abacus 


iiiiii 


3B 




















First Printing, April 1987 
Printed in U.S.A. 

Copyright © 1986 Data Becker GmbH 

Merowingerstr.30 
4000 Diisseldorf, West Germany 
Copyright © 1987 Abacus Software, Inc. 

P.O. Box 7219 
Grand Rapids, MI 49510 

This book is copyrighted. No part of this book may be reproduced, stored 
in a retrieval system, or transmitted in any form or by any means, 
electronic, mechanical, photocopying, recording or otherwise without the 
prior written permission of Abacus Software or Data Becker, GmbH. 

Every effort has been made to insure complete and accurate information 
concerning the material presented in this book. However, Abacus Software 
can neither guarantee nor be held legally responsible for any mistakes in 
printing or faulty instructions contained in this book. The authors always 
appreciate receiving notice of any errors or misprints. 


ATARI, ST, 520ST, 1040ST, TOS, ST BASIC and ST LOGO are 
trademarks or registered trademarks of Atari Corp. 

GEM and CP/M are registered trademarks of Digital Research Inc. 


ISBN 


0 - 916439 - 55-0 


Table of Contents 

Introduction v# 

Acknowledgments vm 

Chapter 1 First steps: Setting up & connecting the ST 1 

1.1 The computer 4 

1.2 The monitor 5 

1.3 The disk drive 5 

1.4 The mouse 6 

1.5 Preparations for start-up 6 

Chapter 2 Working with the ST 9 

2.1 Switching the power on 11 

2.2 The GEM Desktop 12 

2.2.1 Screen arrangement 12 

2.2.2 The disk directory 14 

2.2.2.1 The window 16 

2.2.2.2 Moving the window 17 

2.2.2.3 Changing window size 18 

2.2.2.4 Enlarging and reducing 19 

2.2.2.5 Scrolling 20 

2.2.2.6 Closing the windows 22 

2.2.3 The drop-down menus 23 

2.2.3. 1 Desk 23 

2.2.3.2 File 30 

2.2.3.3 View 37 

2.2.3.4 Options 38 

2.3 Copying diskettes 43 

2.4 Copying and deleting data files and programs 44 

2.5 Multiple windows 46 

2.5.1 From bottom to top 47 

2.5.2 Copying from one window to another 48 

2.6 Icons 49 

2.6.1 Programs 49 

2.6.2 Datafiles 50 

2.7 The keyboard 52 

2.7.1 Typewriter keyboard 52 

2.7.1.1 <Altemate> 53 

2.7.1.2 <Control> 53 

2.7.1.3 <Shift> 53 

2.7.1.4 <Caps Lock> 53 

iii 


2.7.1.5 <Tab> 53 

2.7.1.6 <Esc> 54 

2.7.1.7 <Backspace> 54 

2.7.1.8 <Delete> 54 

2.7.1.9 <Retum> 54 

2.7.2 The function keys 56 

2.7.3 Editing keys 56 

2.7.3.1 Cursor keys (<-»<T>«-><4>) 56 

2.7.3.2 <ShiftxAltemate> cursor keys 56 

2.7.3.3 <Insert> 56 

2.7.3.4 <Clr/Home> 56 

2.7.3.5 <Help> 57 

2.7.3.6 <Undo> 57 

2.7.3.7 <AltematexHelp> 57 

2.7.4 Numeric keypad 57 

2.7.4.1 <Enter> 57 

2.7.4.2 Numbers, math symbols and decimal point 57 

Chapter 3 ST BASIC 59 

3.1 How the ST understands BASIC 61 

3.1.1 What is BASIC? 61 

3.1.2 Loading BASIC 61 

3.2 Windows in BASIC 62 

3.2.1 How windows work in BASIC 62 

3.2.2 Changing ST BASIC windows 63 

3.3 Beginning with BASIC 64 

3.3.1 Directmode 64 

3.3.2 Program mode 65 

3.4 The BASIC vocabulary 66 

3.4.1 print and INPUT 66 

3.4.1.1 Line numbers 66 

3.4.1.2 PRINT 66 

3.4.1.3 INPUT 67 

3.4.2 GOTO 68 

3.4.3 IF...THEN . . ELSE 69 

3.4.4 FOR...NEXT loops 71 

3.4.5 GOSUB...RETURN 72 

3.4.6 REM statements 73 

3.4.7 Clearing the screen 74 

3.4.7.1 Erasing the windows: CLEARW 74 

3.4.8 NEW 74 

3.5 Variables 75 

iv 


3.5.1 Simple numerical variables 75 

3.5.2 Integer and decimal variables 77 

3.5.3 String variables 81 

3.5.4 Dimensioning variables 85 

3.6 ST BASIC graphic commands 87 

3.6.1 CIRCLE A, B,C,D,E 87 

3.6.2 ELLIPSE A,B,C,D,E,F 88 

3.6.3 OPENW n 88 

3.6.4 CLOSEW n 89 

3.6.5 FULLW n 89 

3.6.6 GOTOXY A,B 89 

3.6.7 LINEF A, B,C,D 90 

3.6.8 PCIRCLE A,B,C,D,E 91 

3.6.9 PELLIPSE A,B,C,D,E,F 91 

3.7 Useful BASIC tips 92 

3.7.1 Programmer's aids 92 

3.7.2 Debugging 93 

3.7.3 The EDIT window 94 

3.8 Working with the disk drive in BASIC 96 

3.8.1 Load and Save As 96 

3.8.2 Delete File, Merge and Quit 97 

3.9 First programs 99 

3.9.1 Telephone book 99 

3.9.2 Vocabulary program 102 

3.9.3 The chessboard problem 106 

3.9.4 Lotto numbers 109 

3.9.5 Conversion program 112 

3.10 Summary of fundamental ST BASIC commands 115 

Chapter 4 ST LOGO 117 

4.1 A comparison of LOGO and BASIC 119 

4.2 Loading LOGO 120 

4.3 The LOGO vocabulary 122 

4.3.1 PRINT 122 

4.3.2 MAKE 123 

4.3.3 CS and CT 125 

4.3.4 FORWARD, BACK, RIGHT and LEFT 126 

4.3.5 REPEAT 128 

4.3.6 TO 130 

4.3.7 PENUP and PENDOWN 132 

4.4 More LOGO commands 134 


v 


4.4.1 BOX 134 

4.4.2 CIRCLE 135 

4.4.3 ELLIPSE 135 

4.4.4 HIDETURTLE and SHOWTURTLE 136 

4.4.5 FILLATTRandSETFILL 137 

4.4.6 SHUFFLE and SORT 138 

4.4.7 MOUSE, NODES and TURTLEFACTS 138 

4.5 The ST LOGO vocabulary—review 139 

4.6 Debugging 140 

Chapter 5 A lesson in hiSTory 141 

5.1 The Computer Age 143 

5.1.1 The early days 143 

5.1.2 Cashing in on chips 145 

5.1.3 It's as easy as 1,10,11 148 

5.1.4 What is 512K, anyway? 152 

5.1.5 The function of the microprocessor 154 

5.2 Peripherals, options and possiblities for the ST 156 

5.2.1 Ready for connection 156 

5.2.1.1 The joystick ports 157 

5.2.1.2 Disk drive connection 160 

5.2.1.3 Printer interface and operation 161 

5.2.1.4 The hard disk connection 163 

5.2.1.5 Connecting CD-ROM players 164 

5.2.1.6 The MIDI connections 165 

5.2.1.7 The RS-232 interface 166 

5.2.1.8 The monitor connection 167 

5.2.1.9 The power connection 167 

5.2.2 Software 168 

5.2.2.1 Programming languages 168 

5.2.2.2 Application programs 168 

5.3 Epilogue: The significance of the ST 170 

Appendices 173 

Appendix A: The Atari ST character set 175 

Appendix B: Conversion programs 177 

Appendix C: Mini glossary for computer users 181 

Appendix D: ST BASIC error messages 193 

Index 197 


VI 


Abacus 


Atari ST for Beginners 


Introduction 


Dear ST User: 

We're certain that you're on your way to becoming a genuine computer 
expert. 

After all, you are now reading the book that will familiarize you with one of 
the fastest, most efficient microcomputers on the market today: the Atari ST. 
This is certainly enough reason to call you a future expert! You'll see that it 
won't take long for you to master your ST. 

We'll be using a number of words and phrases that may be unfamiliar to 
you. These words will be printed in italics the first time we mention them. 
First-time computer users may wish to read Appendix C, a glossary for 
computer users, to familiarize themselves with computer terminology. You 
should also keep your ST Owner's Manual handy to look up these terms as 
needed. 

After reading this book, you'll be able to program your computer in both 
BASIC and LOGO, and you'll understand the internal workings of your 
computer. We chose to explore the ST in a way that would make the new 
user most comfortable with it, rather than give you a typical, scientific, and 
throughly boring write-up of the ST. When you thirst for additional 
knowledge after reading this text, you can get more detailed information 
from other books and programs in the Atari ST Reference Library from 
Abacus. 

This book consists of five chapters. Chapters 1 and 2 introduce you to the 
ST. Chapters 3 and 4 introduce you to the programming languages BASIC 
and LOGO. For further information, Chapter 5 holds numerous additional 
facts about the ST. 

Are you ready? Then enough lecturing—let's look at the Atari ST. 

Ranier Liiers 
Michael Stein 

Munster/Bochum 
West Germany 
1986 


vii 



Abacus 


Atari ST for Beginners 


Acknowledgments 

Our special thanks to Dr. Riedel and Atari, GmbH (Germany) who have 
given us a great deal of support while working on this book. Furthermore, 
many Atari users throughout Germany advised us. We would like to 
mention these names in particular: 

Julian Reschke 
Harald Mieling 

We would also like to thank the following people for their help with the 
photographs and artwork in this book: 

Daniel Stoffregen 
Olaf Schellenberger 
Ronald Goergen 

Also, we would like to thank DATA WELT magazine for generously 
supplying us with information and photographic materials. 


viii 



Chapter 1 


-. 

First steps: Setting up & connecting the ST 

__ / 


















































Abacus 


Atari ST for Beginners 


First steps: Setting up and connecting the ST 


You're probably anxious to get your ST up and running, and to start to 
work with some of its advanced features right away. We know from our 
own experience that the first steps taken in computing are usually the ones 
where the most frustrating mistakes occur. To minimize these problems, 
we'll begin this chapter by showing you how to connect the components of 
your ST, thereby avoiding some potentially expensive errors. 

There are currently two different models of the Atari ST. The first, the 
520ST, can be purchased as a set of components: the computer and its 
power supply, a color or monochrome monitor, one or two disk drives, and 
a mouse. The second model, the 1040ST, comes complete with a built-in 
disk drive and built-in power supply. All you need is a monitor and a 
mouse. 

NOTE: A third ST model is available in Europe. Called the 260ST, this 
computer is identical to the 520ST in every respect except memory 
capacity. Therefore, any reference to the 520ST also applies to the 260ST. 

Once your ST is assembled, it should look something like this: 



The 520 ST computer system 


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Abacus 


Atari ST for Beginners 


Our next step is to connect the components of the ST. Since there are 
differences between the 520ST and 1040ST, we'll discuss the procedure for 
each model as we go along. Do not plug in the 520ST power supply 
or the 1040ST power cord (or the monitor's power cord) until 
you complete the steps for connection outlined below. 


1.1 The computer 



520ST—rear view 

We've numbered the connections on the back of the 520ST so that they are 
clearly recognizable. The power supply connector cord is plugged into 
socket 5. Make certain that the small alignment notch of the power supply 
plug points upward when you plug it into the ST. Note: Newer 520ST's 
will have an additional jack between 6b and 7. This standard RCA jack is 
connected to an RF modulator, and lets you use a television set instead of a 
monitor with the 520ST. 

The 1040ST's connections are a little simpler: 


rrm a r- rrnrrrrm r rrrrrrr rrrrrrrrrrrrrr rrrrrrrrrrrrrn • 



1040ST—rear view 

The power cord for connecting the 1040ST to standard electrical current is 
plugged into jack 7 of the computer. There is no external power supply like 
with the 520ST. 


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Atari ST for Beginners 


1.2 The monitor 


The connector cable of the monitor is plugged into the monitor at its right 
rear. The cable that's attached to the monitor plugs into socket 7 of the 
520ST computer. The monitor cable plugs into socket 5 of the 1040ST. As 
with the power connector, the small alignment notch on this cable must 
point upward when plugged in. 


1.3 The disk drive 


The disk drive has to be connected to the ST and to its own power supply. 
Plug the power supply cord into connection 3 of the disk drive, with the 
alignment notch upward. Plug the grey cable that came with the disk drive 
into connection 1 of the disk drive. Plug the other end into connection 10 of 
the 520ST. If you're a 1040ST owner, you already have an internal disk 
drive. If you are using second disk drive, plug it into connection 4 of the 
1040ST. If you only need one drive, go directly to Section 1.4. 


If you purchased two disk drives for your 520ST, connect the first drive as 
above, then connect the second disk drive to the power supply. Plug the 
grey cable supplied with the second disk drive into connection 2 of the first 
disk drive. Plug the other end into connection 1 of the second disk drive. 



Disk drive—rear view 


5 








Abacus 


Atari ST for Beginners 


1.4 The mouse 


Now we'll connect the mouse, that palm-sized input device with the short 
cord. There are two jacks on the right side of the 520ST. Connect the 
mouse to the port marked 0. 1040ST users must tilt the computer up, then 
plug the mouse into port 0 (this port is recessed in the bottom of the 
computer). The illustration below shows ports 0 and 1 on the 1040ST: 



Mouse and joystick ports—1040ST 


1.5 Preparations for start-up 


For added convenience you may want to use a multiple-outlet strip to 
connect the various power cords used by the ST. Before plugging in the 
monitor and the ST power supply, make certain that all equipment is 
switched off . Important: make sure you remove the inserts from 
your disk drive(s) before you turn on the power. 

The power switch is located on the back of the computer—number 4 in the 
photograph of the 520ST, and number 6 in the 1040ST photograph (see 
photographs on page 4). 


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Atari ST for Beginners 


The monitor’s On/Volume switch must be set to "Off'. The disk drive 
On/Off switch is in the drive's back. Insert the diskette labelled Language 
Disk into disk drive A (see photograph below): 



Inserting a disk 


Finally, plug in the power cords of the hardware. Then switch on the 
electrical components in the following sequence: 

1. Monitor 

2. Disk drive 2 (if you own one) 

3. Disk drive 1 (520ST only) 

4. Computer 

Now you're ready to move on to Chapter 2. 


7 





















Chapter 2 




\ 


Working with the ST 




J 
































































Abacus 


Atari ST for Beginners 


Working with the ST 


2.1 Switching the power on 


When you switch on the ST system's power, the following display pops up 
on the monitor screen. Your monitor screen may not look exactly as 
pictured. This depends on which monitor you have connected—color, 
monochrome or television set—as well as the screen resolution mode. If the 
objects appear twice as large as shown in the screen pictures, then you are 
in low resolution color mode. If the display does not appear, try adjusting 
the two upper knobs on the right side of the monitor to change the 
brightness and contrast. If you get no improvement, repeat the set-up 
instructions in Chapter 1. 



The ST's operating system is activated when the computer's power is 
switched on. Put simply, the operating system tells the ST what it’s 
supposed to do (how it is to operate). All messages and information which 
we receive from the ST are contained in this operating system. The ST is 
unable to function without an operating system. 


11 





Abacus 


Atari ST for Beginners 


2.2 The GEM Desktop 


A narrow white line appears on the top border of the screen and displays the 
words Desk, File, View, and Options. This is the menu bar. 

Beneath the menu bar are several pictures called icons. Imagine these icons 
as corresponding to items on your desk. Two disk drives are on the 
Desktop, and a trash can is on the floor. Think of the disk drives as file 
cabinets—note that the ST even displays your disk drives as file cabinet 
icons. We'll use this comparison later on in the chapter. 


2.2.1 Screen arrangement 


Don't like the arrangement of your Desktop? No problem. Notice that if you 
move the mouse on your work surface, a little arrow called the mouse 
pointer moves accordingly on the screen. Move the mouse pointer until it is 
positioned over one of the disk drives, then press and hold down the left 
mouse button. The ST acknowledges this action by reversing the color of 
the disk drive icon. This pointing and clicking action is know as selecting. 



12 





Abacus 


Atari ST for Beginners 


Now while holding down the left mouse button, move the mouse pointer to 
the right. A ghost icon , or silhouette, of the disk drive also moves to the 
right. If you release the mouse button now, the icon itself moves to the new 
location. At first only the ghost icon was moved, but as soon as you release 
the mouse button, the ST moved the icon to the new Desktop location. This 
procedure of moving an icon from one location to another is called dragging 
the icon. 



Try moving the trash icon to another screen position. Dragging an icon is 
one of many tasks that the operating system performs. In reality, the 
dragging movement is not taking place on the monitor itself, but being 
processed and calculated inside your ST. 

Be careful not to drag one of the disk drive icons over the other. If you do, 
the ST will attempt to perform a disk copy—and we aren't ready for that 
yet! If this happens accidentally, when the alert box appears on the screen, 
move the mouse pointer to the dialog button marked CANCEL and click this 
button. This will prevent an accidental disk copy. 

If you try to drag a disk drive icon to the trash can, or the trash can to a disk 
drive icon, the ST will inform you that you cannot perform this operation. 
An alert box will appear on the screen to tell you that you made an error. To 
continue, move the mouse pointer to the OK dialog button inside the alert 
box and click the left mouse button. 


13 







Abacus 


Atari ST for Beginners 


Desk File Uiew Options 



The ST's operating system is designed to be very easy to use. It endeavors 
to be very polite and informative as you perform various operations. 


2.2.2 The disk directory 


To find out which files are on a diskette, move the pointer to the desired 
disk drive icon (labeled FLOPPY DISK) and press the left mouse button. 

The disk drive now appears in reverse video, indicating to the ST that you 
want to perform some operation with this device. Now press the left mouse 
button twice in quick succession. This is called double-clicking. The 
diskette in the disk drive should start to spin and the disk's directory will 
appear on the screen. 

If the directory does not appear on the screen, don't worry. It takes practice 
to be able to double-click. Try to double-click the icon again. If you 
continue to have trouble, there is an alternate way to open a diskette. 


14 















Abacus 


Atari ST for Beginners 


Click the desired disk drive icon once so that it is displayed in reverse 
video. Move the mouse pointer to the word File on the menu bar. A 
drop-down menu will appear (see section 2.2.3 for details on and 
illustrations of drop-down menus). Now move the mouse pointer to the 
word Open and press the left mouse button again. 

Selecting Open from the drop-down menu File is equivalent to 
double-clicking the disk icon. In either case, a new window will appear on 
the screen, as shown below: 



The disk currently in the disk drive contains individual program files or data 
files. A list of these filenames appears in the window. You may select the 
program with which you want to work from this group of files. This list is 
called the disk directory. 

Now look closely at the disk directory window. Remember when we 
rearranged the icons on our Desktop? We can also change the window's 
location and size. 


15 
















Abacus 


Atari ST for Beginners 


2.2.2.1 The window 

A window is part of a screen which contains information about the work 
with which you are dealing. There are several functions which you can 
perform on an individual window. There is an illustration of a typical 
window at the bottom of this page, and the locations and names of these 
functions, or attributes. These terms and their functions shall be defined as 
you read on. 



A typical window and its components 


16 






























Abacus 


Atari ST for Beginners 


2.2.2.2 Moving the window 

Move the mouse pointer to the top line, or move bar, of the window. This 
bar is labeled with the letter A: \ in the center. The A: \ means that this 
window is the directory of the diskette in drive A. 

Position the mouse pointer on the move bar, press the left mouse button and 
hold it down. When you move the mouse, the entire disk directory window 
also moves. We can drag the entire window this way, just as we did earlier 
with the individual icons. 

Desk File View Options 



Now release the mouse button. The entire window is now shifted to its new 
position on the screen. You can even move it so that it "hides" the disk drive 
and trash can icons. 


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Abacus 


Atari ST for Beginners 


2.2.2.3 Changing the window size 

You've probably noticed the other symbols along the border of your disk 
directory window. These symbols change the size of the window. To fill 
the entire screen, move the mouse pointer to the box at the upper right 
comer of the window (the full box). Then click the left mouse button (do 
not hold it down this time, just click it once). Now the window occupies the 
entire screen. 



If you click the full box again, the process is reversed. Now we see only 
part of the disk directory. 

Note: The full box is similar to an On/Off switch. When it's in the On 
position the window is enlarged. Clicking it Off again returns the window 
to its previous size. 


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Abacus 


Atari ST for Beginners 


2.2.2.4 Enlarging and reducing 

The small symbol at the bottom right comer of the window (the size box ) 
gives you more control over the window's size. Move the mouse pointer to 
this box, press the left mouse key and hold it 

Now move the mouse back and forth on the desk. You can change the size 
of the disk directory window quickly and easily in this way. 



Reduce the window to its smallest size using the size box. Hold down the 
left mouse button while the mouse pointer is on the size box, move the 
mouse pointer to the upper left-hand comer of the screen, and release the 
mouse button. 


19 











































Abacus 


Atari ST for Beginners 



Now we only see a small portion of the directory. If you want to enlarge the 
disk directory, drag the size box to the right with the pointer. You also may 
return the disk directory to its original size by the repeatedly clicking the 
mouse on the size box, or by dragging the size box down and right. 


2.2.2.5 Scrolling 

You don't really need to do all this stretching. The scroll arrows , two on 
the right of the window and two on the bottom, let you scroll through the 
window’s contents. A portion of the bars running along the bottom and 
right edges of the window, or scroll bars, will be shaded when files are 
hidden from view. The unshaded portion is what is being viewed presently, 
the shaded portion is the part that is now visible at the present time. 

Make the disk directory window as small as you can. Move the mouse 
pointer to the scroll arrow at the bottom right, and press the mouse button. 
The next segment of our disk directory becomes visible. Do the same with 
the other scroll arrow. Although the window can only show a small picture 
right now, you can see the entire directory by scrolling down and right with 
the scroll arrows and scroll boxes. 


20 
























Abacus 


Atari ST for Beginners 



"Great," you wonder, "but what good is that?" Well, this allows you to 
have several disk directories on the screen at once. The scrolling allows you 
to view and compare the contents of the different disk directories. 



386351 bytes us 


New Folder 


Close HindoH 


Fomat 


5B6351 butes us 


386351 bytes us 


586351 bytes us 


View Cptions 

Open 

Show Info,,, 


Desk 


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Abacus 


Atari ST for Beginners 


2.2.2.6 Closing the windows 

The upper left comer of our window is called the close box. The close box 
removes the window from the screen, i.e., closes the window. 

Click the close box with the mouse. The disk directory vanishes and the 
desk is clear. Now, as when you turned the power on, there are only two 
disk drive icons and one trash icon on the desk. The window with the disk 
directory has "disappeared" into disk drive A. 


Desk File VieH Options 



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Atari ST for Beginners 


2.2.3 The drop-down menus 


Now let's look at the menu bar— Desk, File, View, Options. 


2.2.3.1 Desk 

First, move the mouse pointer with the help of the mouse to Desk. A 
menu of available functions is displayed. This type of menu is called a 
dr op-down menu. This Desk menu contains the Desktop Info... 
selection. It also contains what are known as desk accessories, which are 
loaded from the Language Diskette. If you started your ST with the 
Language Diskette in (hive A, the following information can be seen: 



Move the mouse pointer to Desk on the menu bar, then move the mouse 
pointer to Desktop Info.... The Desktop Info... will be displayed in 
reverse video when the mouse pointer moves over it. Select Desktop 
Info... with the mouse and the following appears: 


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Abacus 


Atari ST for Beginners 



6EH, Graphics Environnent Manager 


Copyright (c) 1985 
ATARI CORP. 
Digital Research, Inc 
All Rights Reserved. 




This displays a dialog box containing information about the TOS and GEM 
operating systems in the ST. 

You've probably already heard about GEM (Graphics Environment 
Manager). GEM is the part of the operating system that controls the 
different graphic functions (for example, it draws the four comers of the 
disk directory window). Once you have read the information on the screen, 
move the mouse pointer to the OK and press the left mouse button. This 
window disappears from the screen. 

Now we'll describe the other choices we have under the Desk heading. 
These are desk accessories that are loaded from the diskette in drive A when 
the computer is first turned on. The standard set of desk accessories that are 
included with the ST are described below. If you want to use these 
functions of your ST later, you'll find the necessary information here. 


24 











Abacus 


Atari ST for Beginners 


VT52 Emulator 

If you select the VT52 Emulator with the mouse, the graphic screen 
disappears and the following message appears: 


xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 

I Atari VT52 Terninal Enulator 
I (c) Atari Corp. 

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 

Press: 

1) UNDO to return to desktop. 

2) HELP to configure terninal. 


The VT52 emulator is a terminal emulator program that lets you 
communicate with other computers via the RS-232 port or by modem (see 
Chapter 5 of this book). For example, you can use the VT52 emulator 
program to communicate over telephone lines with large corporate 
mainframe computers. 

If there is no modem or other computer connected to your ST, press the 
<Undo> key on the right side of the keyboard to exit this accessory. 

If you wish to establish a connection via the RS-232 port, you not only 
have to click on VT52 Emulator with the mouse, but also configure the 
Set RS232 Conf ig . for proper transmission and reception. You can do 
this directly from the running VT52 emulator program if you press the 
<Help> key on the right side of the keyboard. 


25 





Abacus 


Atari ST for Beginners 


Set RS232 Config. 

You can also select Set RS232 Config. in the Desk drop-down 
menu. This option displays another menu on the screen: 


RS232 PORT CONFIGURATION 


Baud Rate: | 


1 4880 II 1200 II 3GB 

Parity: | 

None 

1 Odd II Even] 

Duplex: 

TulT 

IlHalTI 

Bits/Char: 

8 

II 7 || 6 5 

Strip Bit: 

On 

ygfl 


Flow Control 


Xon/Xoff: On 
Rts/Cts: 


On 


OK 


I Cancel I 


Now you may select different options located next to one another (for 
example, transfer rate at 9600, 4800, 1200 or 300 baud). Move the mouse 
pointer to the desired option and press the left mouse button. The different 
options are used to configure the RS-232 port on the back of the computer. 
This port is used to connect various peripherals to your ST, such as 
printers, modems and plotters. 

The selected box is highlighted in reverse video (e.g. white type on black 
background) to confirm the choice. Once the configuration is complete, 
move the mouse pointer to the OK dialog button at the bottom left and click 
to confirm. If the configuration was wrong, click the CANCEL dialog button 
on the right hand side. 


26 





































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Atari ST for Beginners 



INSTALL PRINTER 


Printer Type: HUS I Dai 

Color: HIBB I Col 

Pixels/Line: I 128B I T? 

Quality: I Draft 1 hni 

Printer Port: fJJliUjJ I Hod 

Paper Type: I Sim 

I OK I I Cancel I 


Final 


Printer 


Install Printer 


This option lets you specify how your printer is set up. If you want to set 
up your printer at this stage, then follow these directions: 


Desk File mew Options 


Here Install Printer needs to know whether your printer is 
dot-matrix or daisywheel, color or black & white. It's important to set 
Pixels/Line to 960, and Quality to Final when using Epson and 
Epson-compatible printers for hardcopy (screen dumps). Otherwise the ST 
prints only part of the screen. If your printer is designed to use the RS-232 
interface, set the Printer Port to Modem. Centronics interfaces 
(parallel) use the Printer selection. Also select whether you are using 
continuous form paper (Feed) or single sheets of paper (Single). 

If you're a little confused by all of this "computerese", don't worry. We'll 
explain the operation of printers in detail later on. 


27 






























Abacus 


Atari ST for Beginners 


Control Panel 

The Control Panel is another function of the Desk menu: 



You can use the Control Panel to set: 

• time and date 

• key repeat delay 

• keyboard repeat speed 

• key click 

• bell 

• color 

• mouse double-click speed 

If you have a color monitor, color tint adjustments are made with the three 
RGB (red-green-blue) color palette controls on the left side of the Control 
Panel. 

Monochrome monitor users have only two screen colors available: white on 
black, or black on white, selected with the three palette controls. Move the 
controls with the mouse pointer in the direction opposite the shade you 
desire. 


28 















Abacus 


Atari ST for Beginners 


Here are the rest of the Control Panel options: 

Clock : Move the mouse pointer into the clock window and click the left 
mouse button. The time is displayed in reverse video to mark your 
selection. Erase the old time with the <Backspace> key (or press <Esc>), 
and enter the current time. You confirm this by clicking the time field with 
the left mouse key, or by pressing the <Retum> key. 

Calendar : Same as the clock function. Your ST will display any data you 
enter, so be sure to enter it correctly. 

Keyboard Response : Moving the slider on the upper side adjusts the delay 
between keypress and key repeat. The lower slider controls the speed at 
which the keys repeat. 

Mouse Click Response : The icons are self-explanatory. Position 0 (mouse 
at rest) produces slow double-clicking. Position 4 requires quick reflexes to 
do a double-click. Position 2 or 3 should be right for you. 

Audio Feedback : These two symbols may be switched on or off by the 
mouse. The bell rings to indicate an error; the key click sounds when you 
depress a key. Although both functions are valuable as controls, we advise 
you to turn the volume adjustment on the monitor as far down as possible, 
instead of adjusting volume from the Control Panel. 

We mentioned the color palette (RGB) sliders earlier. Using them, you can 
store up to 16 colors in the lower part of the Control Panel, and call 
them up again with the mouse. (These 16 blocks have no meaning on 
monochrome monitors). 

Finally, we should mention the CANCEL dialog button in the control panel. 
If you don't like your changes, click the CANCEL dialog button. All values 
except date and time are immediately changed to their original status. 

You may move the Control Panel window around the screen by 
clicking on the hatched area of the window and pulling. Close the 
Control Panel window the same way you closed the disk directory 
window—click once in the close box at the upper left comer. 


29 



Abacus 


Atari ST for Beginners 


2.2.3.2 File 


Now we'll look at the File menu. Click drive A's icon with the mouse 
pointer to select drive A, then move the pointer to File on the menu bar: 



Open 

The Open option allows us to run a program or examine the contents of a 
diskette, folder or file. This function is useful because some users, 
especially beginners, have difficulty when double-clicking the mouse 
button, even at low speed. Open lets you open a selected disk or file from 
the File drop-down menu with only a single click. 

If you point to Open with the mouse pointer and then press the left mouse 
button, the directory of disk drive A is displayed: 


30 










Abacus 


Atari ST for Beginners 



Show Info 

The Show Info function displays information about a Desktop icon or a 
file. If you select a disk drive icon, then Show Inf o, a dialog box appears 
with the following information: the number of folders and files on the 
diskette, how much memory is occupied by files and programs, and how 
much memory is still available. 

This is for informational purposes only. You can't make any changes. Click 
the OK dialog button to close this dialog box. Move the mouse pointer to a 
disk drive icon and double-click the icon to open a disk directory. Click a 
file icon to select it, then click Show Info. 


31 





















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Atari ST for Beginners 



Disk information 


Options 



Item information 


32 


mm 











































Abacus 


Atari ST for Beginners 


To change a filename, press the <Backspace> or <Esc> key to delete the 
current filename. Then use the keyboard to enter the new filename. You 
may also designate files as READ/WRITE or READ ONLY. Confirm by 
clicking the OK dialog button. 


New Folder 

A folder organizes your files on a diskette. If you have a number of related 
files, you may want to put them together in one folder to keep the Desktop 
orderly. To create a folder, first open a disk directory, then select New 
Folder from the File menu. The following dialog box is displayed: 



Enter a name for the folder, such as ACCESSORIES. Then click the OK 
dialog button. The new folder will be created on the currently open disk 
drive. After it is created you will see an icon representing the folder on the 
disk directory. 

If you're still using the original Language Diskette, it is write-protected, to 
keep changes from being made accidentally. After you clicked the OK dialog 
button, the ST informs you with an alert box that it cannot perform this 
function because the disk is write-protected. The write-protect tab is a small 
plastic slider on the back of the diskette: 


33 



























Abacus 


Atari ST for Beginners 



Write-protect tab 

Once the tab is moved so that the square hole through the diskette is open, 
the diskette's contents cannot be changed. 

If your write-protect was "up" (the square hole was closed) and you clicked 
OK, you now have a folder with the name ACCESSORIES. The folder can 
be opened in the same way that a diskette is opened. First select the folder, 
then either double-click or select Open from the File menu. If you open 
the ACCESSORIES folder you will see that it is empty. We'll see how to 
copy files into this folder in Section 2.4. 


Close and Close Window 

These two options are methods of closing a window. Simply click either of 
these options from the File menu. Clicking the window's close box is 
another way of closing the window. 

It's a good idea to keep windows closed when they are not in use, since 
they can clutter up the Desktop. 


34 











































Abacus 


Atari ST for Beginners 


Format... 


Formatting does more than erase diskettes. When you purchase blank 
diskettes, they are really blank—they cannot be used "as is" in the ST. 
Formatting divides or formats the diskette into tracks and sectors for data 
storage on a particular computer system. To format a diskette, first remove 
the diskette in drive A and insert a new blank diskette. Next select the 
floppy disk drive icon for drive A, then select Format... from the File 
menu. The following alert box is displayed: 



View Options 


□ □ - - n n 

CONTROL.ACC EMULATOR.ACC BASIC.PRO LOGO.PRO NEO.PRO SAMPLE.PRO SLID 

n d____ 

BASIC.RSC LO< 

Al 

Formatting will ERASE all 
the information on the disk 
in drive A:. Click on OK 
only if you don't mind 
losing this information. 

I OK ^ | |Cancel] 



wmmm 


Make sure that the system diskette is removed from drive A and a new blank 
diskette is inserted. Then click the OK dialog button. 

There are two disk drive models available for the ST. The SF354 is a 
single-sided drive that reads the bottom side of a diskette. The SF314 is a 
double-sided drive that reads both the top and bottom of a diskette. The 
1040ST has a built-in double-sided drive. After you click OK the following 
dialog box appears. Insert a diskette, input a disk name and select single- or 
double-sided, and click FORMAT: 


35 




























Abacus 


Atari ST for Beginners 



Format program 



Formatting in progress 


36 






























Abacus 


Atari ST for Beginners 


When the process is complete, a message appears: e.g. 357 37 6 bytes 
are available (for a single-sided diskette). You can now format more 
diskettes or EXIT this procedure. 


2.2.3.3 View 

Let's open a diskette containing files and have a look at the menu marked 

View: 



Show as Icons 
Show as Text 
Sort... 

Here you choose how the diskette directory appears on the screen. Also, the 
directory can be sorted by filenames, dates, file sizes or file types. 

Your choice is executed immediately, so the change may be seen as soon as 
you select your choice. The system marks your choice with a check mark. 
Try out the various options to see the results. 


37 
































Abacus 


Atari ST for Beginners 


2.2.3.4 Options 

Select disk drive A before choosing this menu. The following will appear: 



This menu performs a variety of useful tasks, such as adding a disk drive, 
installing an application program, saving your control panel and Desktop 
settings onto a diskette, and getting a printout of the current screen display. 


38 




































Abacus 


Atari ST for Beginners 


Install Disk Drive... 



Options 






Desk File View 


306351 bytes used in 9 itens, 


INSTALL DISK DRIVE 

Drive Identifier: D , 

Icon Label: RflH-})ISK- 

llnstal^ I I Remove I I Cancel I 


You can now change the disk drive name under a drive icon, and even the 
diskette name itself. This is useful for adding hard disks and RAM disks 
(more on these later). You can also Remove the diskette from the screen. 
Be careful with this selection—once you have erased the two drives, you 
cannot use your system diskette anymore. Try renaming the icon label for 
FLOPPY DISK to 3 1/2" DISK. 


Install Application... 

This function appears in grey on the screen, and cannot be accessed at the 
moment. Only functions with black lettering can be clicked. 

To use this function, you have to select a program from the directory 
(programs have . TOS or . PRG extensions which follow the filename itself, 
and are marked as block icons). 


39 


























Abacus 


Atari ST for Beginners 



306351 bytes used in 9 itens 


INSTALL APPLICATION 


Application Nane 
Document Type 


Application Type 


i OEM I ■!»« 1 TOS-takes paraneteril 


I OK ^ I I Cancel I 


Options 


Desk File Vie* 


The ST can run both programs which use GEM, and programs which don't 
use this graphic interface. These programs run without icon control from 
GEM, which means that they run under the TOS operating system only, 
bypassing GEM altogether. 

Install Application . . . allows you to determine what type of file 
will directly start programs (those with . PRG extensions), and allows you 
to choose the operating mode (GEM, TOS or TOS takes parameters). 

We can now enter the document type. This tells the operating system that 
you want files with a particular filename extension to start the application 
program you've installed when these files are opened. Programs (.PRG, 
.TOS and .TTP) can be automatically started by opening them, but data files 
can also be started with a "document type" extension. When these files are 
double-clicked, the installed application program, then the files themselves, 
are loaded in to the computer. For example, give a program that runs in ST 
BASIC a .BAS extension. Select Install Application . . . and then 
install BASIC .PRG with a document type of BAS. Now when you select a 
file with a . BAS extension, the ST will load BASIC. PRG, then the file you 
selected will load and run. 


40 

































Abacus 


Atari ST for Beginners 


Set Preferences.. . 



FLOPPV DISKgFLOPPV DISK 


Desk File View liffil" 


0UD03X uy it-3 u 

□ l 

i 

A IUIJ 1 

P| 

ftl 

| CONTROL.ACC KMULf 



-*»LE.P1ta SLID 


□ 1 

SET PREFERENCES 



BASXC.RSC LO< 

Confirn Deletes: |2£| 1 No I 




Confirm Copies: DSI 1 No 1 




Set Screen Resolution: 




I Lon | iHediunl IHTlil 



Ur 


OK ^ 1 Cancel 1 


rl 


The ST always asks if you actually want to delete a file, or if you wish to 
copy a file or diskette. If you are absolutely certain of how to handle 
deleting or copying of files, you may click the NO dialog buttons at 
Confirm Deletes or Confirm Copies. This will speed up. these 
procedures— but remember, you will run a much greater risk of 
losing your valuable data. 

As mentioned before, the ST has three different screen resolutions. You can 
only use High resolution on a monochrome monitor. You can only use 
Low and Medium resolutions on color monitors. 

Entries are confirmed by clicking OK, and cancelled by clicking Cancel. 


41 








































Abacus 


Atari ST for Beginners 


Save Desktop 

The changes made to the desktop up until now have only been temporary 
(e.g., Control Panel, RS-232 Config., Show.., SORT..., 
Set Preferences). If you pressed the reset button, or if a power failure 
occurred, all these changes would be lost. 

To make changes permanent, you can Save Desktop, which saves all 
options and the location of the icons and open windows. This data is saved 
to a file called DESKTOP . INF. Every time the computer system starts up, 
this file is loaded from the boot diskette. Thus your changes can be made 
permanent by saving the Desktop. 


Print Screen 

This option prints the current screen on your printer. You must have a 
printer capable of printing graphics connected to the Centronics parallel 
port. The Printer Port must be set to Printer (see Install 
Printer from the Desk menu). This screen printout is known as a 
screen dump. 

Pressing <Altemate> and <Help> simultaneously on the keyboard will also 
produce a screen dump. 


42 



Abacus 


Atari ST for Beginners 


2.3 Copying diskettes 


Now let's copy the Language Diskette. If you haven't formatted a blank 
diskette yet, turn back to page 35 (Format). Note: Even if you have a 
double-sided drive, you must still format the backup as a single-sided 
diskette. The double-sided drive will read both formats. The one supplied 
by Atari is formatted as single-sided so that both drive models can read it. 

Click the mouse pointer on drive A, and drag drive icon A to disk drive B. 
A confirmation message appears on the screen before the copy procedure 
begins. Click OK to continue, or CANCEL to exit. 



396351 bytes used in 3 itews 


CONTROL • ACC EMULATOR .ftCC BftSIC.rRCI 


I OK ^ I I Cancel I 




Copying disk f): to disk B: 
Hill ERASE all the 
infornation on disk Bi. Click 
on OK only if you don't nind 
losing this infornation. 


If you click OK, another dialog box will appear. The copying procedure 
from here is simple if you have two disk drives. Insert the original diskette 
(in this case the Language Diskette) into drive A, and the destination diskette 
(the formatted diskette) into drive B. Then click COPY. 

If you have only one disk drive, click COPY, then exchange diskettes in 
drive A when the ST tells you to switch diskettes (the original diskette is A, 
the destination diskette is B). The ST loads the contents of the original 
diskette into memory, then saves these contents to the destination diskette. 


43 
























Abacus 


Atari ST for Beginners 


2.4 Copying and deleting data files and programs 


Individual files are copied by clicking an individual icon in the directory, 
and dragging it either to the drive B icon or the drive B directory. A 
message similar to the copy message appears, and you perform the copying 
as outlined in Section 2.3. 

You can also copy programs and files into folders. Drag the files by holding 
down the mouse key and moving the ghost icon onto the folder. 

Each time you want to place a file into the folder, a message requesting 
confirmation appears on the screen. Click OK. You can then check the 
contents of a folder by pointing at and double-clicking it to open the folder. 
If all is correct, close the folder by clicking its upper left comer. The files 
which you placed in the folder now exist in two places: in the folder, and in 
their original locations in the directory. Delete the originals by dragging 
them to die trash can. 

You can also copy data files and programs on the same diskette. Your ST 
advises you to change the filename before the copy is finished as below: 



3B6351 bytes used in 3 itens 


CONTKOL.rtCC 


NAME CONFLICT DURING COPY 


j OK 1 I Cancel ! 


Desk File View Options 


Current Nane: EMULATOR. ACC. 
Copy's Nane: EMULATOR. ACq 


44 







































Abacus 


Atari ST for Beginners 


Files can be deleted individually by dragging them to the trash can. Open the 
disk directory and drag the program or file to be deleted to the trash can 
(place the file over the trash can icon). 

There is a danger in deleting files. If you accidentally throw away some 
papers at home, you can search the wastebasket and (hopefully) find the 
discarded item. But once you drag a file to the ST's trash icon, it's 
irretrievable-gone forever. Be careful! 

Several files can be deleted at once. Mark the files by framing them, i.e., 
pressing and holding the mouse key starting from top left of the window. 
This "lassos" the group of files—they can be copied or trashed all at once. 
This group of ghost icons will move together for copying or deletion. Use 
the mouse arrow to position the group over the correct destination icon 
(folder, diskette or trash can). 

Desk File View Options 



You can also select a group of files by holding down the <Shift> key and 
clicking each file. All files will move together for copying or deletion. 


45 































Abacus 


Atari ST for Beginners 


2.5 Multiple windows 


Until now we have only opened one window on the screen, to display the 
current disk directory. But the GEM operating system lets you open up to 
four windows at once. 

Double-click disk icon A four times. This gives you four disk directories. 



CONTROL•ACC EMULATOR.ACC BASIC.PRO 


CONTROL 


Desk File View Options 


3B6351 bytes used in 9 itens, 


386351 bytes used in 9 itens, 


mu 


386351 bytes used in 9 itens. 





ji 


“l 


B 


8 HUS 


to acsra n:\ i 

1 : 

! , « I 

:; , 

la 

| 386351 bytes used in 9 itens. 


Your screen will look crowded. The ST has stacked the four directories as if 
they were four sheets of paper piled atop one another. The window margins 
of the top page are visible (e.g., close box, move bar, etc.), while the other 
three pages have no margins. It's possible to change the size of the current 
directory using the size box. We can also move the directory to another 
position, or close it. 

As you probably already found out, your ST remembers all the information 
contained in the hidden (or partially hidden) disk directories. If you move 
the current directory, the hidden pages become partially or completely 
visible. 


46 

























































Abacus 


Atari ST for Beginners 


2.5.1 From bottom to top 


You can easily call up one of these hidden directories for viewing. Move the 
mouse pointer to any point on another disk directory, and click the left 
mouse button. The selected directory is brought to the top and the other 
directories are moved behind it. 


Desk File View Options 



The ST can have only four windows open at once. If you attempt to open a 
fifth window, you will get an alert message. One of the windows must be 
closed before you open another. Click OK. 

You may not need four windows at once, but some applications make use 
of multiple windows. There are ST programs on the market that use four 
windows for calculations ( PowerLedger ), data management 
( DataRetrieve ), and graphics ( PaintPro). 


47 






























































Abacus 


Atari ST for Beginners 



3B6351 bates used in 3 itens 


CONTHO 


Desk File View Options 


The GEM Desktop has no wore 
windows, Before you open a 
disk, close a window that 
you're not using. 


30635 


on 


2.5.2 Copying from one window to another 


Multiple windows let you copy files from one disk directory to another. 
This is useful for copying files into folders on the same diskette. One 
window shows the main directory while the other window shows the 
contents of the folder. 

If you only have a single disk drive, this one drive acts as drives A and B. 
This means that you will have to exchange disks when prompted to do so 
by the system. 

However, if you own two disk drives, you simply put the source disk into 
drive A and the destination disk into drive B—the ST does the rest. A hard 
disk or RAM disk is represented by drive C. Multiple windows help this 
process. 


48 




























































Abacus 


Atari ST for Beginners 


2.6 Icons 



We have already mentioned icons. There are three types of file icons: the 
folder, the block with the darkened top border, and the pile of paper with 
the comer of the top sheet folded over. We have already worked with the 
folder icon, so we'll discuss the other two file icons now. 


2.6.1 Programs 


The block with the dark upper border has one of three file extensions: . PRG 
(program), .TOS (Tramiel Operating System) or . TTP (TOS takes 
parameters). This means that the program either operates under GEM (up to 
4 windows and graphic interface: .PRG), or without GEM (.TOS or 
.TTP). 

Double-click the mouse on a .PRG program icon to open a program. The 
screen turns dark, the pointer turns into a busy bee, and the program loads 


49 














































Abacus 


Atari ST for Beginners 


into memory. After a few seconds, the opening screen of the program 
appears. Programs with . TOS extensions will clear the screen when they 
are opened. Programs with . TTP (TOS takes parameters) extensions will 
first display a dialog box requesting input of parameters; these parameters 
vary depending on the program. 


2.6.2 Data files 


The stack of papers with the top sheet folded represents a datafile. A data 
file may be a BASIC or LOGO program file (i.e., a program created in one 
of these languages, and not necessarily from the operating system), a word 
processing file, or a database file. 

Files can also be complex subroutines, automatically loaded by a main 
program (block icon). Screen graphics can be stored as data files. These 
files have a .PIC extension, and are recognized by the program used to 
create them. 

Open the BASIC. RSC file by double-clicking it. The ST displays the 
following information: 



306351 butes used in 9 itens 


CONTROL.*CC EMU 


floppv diskjIfloppv DISK 


k Desk File View Options 




You can only print or display 


this docunent. Please click 

’LK.RIta SL1 

on appropriate button to 


do so. 


1 ShoH I | Print 1 (Cancel I 

mmm o 


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Abacus 


Atari ST for Beginners 


If the master program was not available with the file, the file is not loaded. 
You could CANCEL the procedure or Show the file. If you click Show the 
first line of your screen would look like this: 


Td$vr (Desk File Run Edit Debug About ST BASIC-De 

This file is read directly after a matching main program (BASIC. PRG) is 
loaded. The ST can make direct use of this material—all we can do is see it. 

The next example is a text file. If the program had been shorter than the 

screen,- END OF FILE -would have appeared on the screen 

instead of -MORE- . To see more of the file, you would press <Enter> or 
<Retum> to see the next program line. Press the spacebar to display the 
next screen of the file. Other files that can be viewed like this are usually 
BASIC programs (. BAS extension), LOGO programs (. LOG extension) or 
word processing files (mostly . DOC or . TXT extensions). 

1ST WORD RELEASE NOTE 
VERSION 1.02 


This disk contains 1st Word, the GEM word processor written by 
GST of Cambridge, England and supplied with your Atari ST 
computer. 

In order to provide you with a fully working word processor as 
soon as possible, the 1st Word User Guide has been supplied on 
the microfloppy disk together with the 1st Word software. 

Backing up 

Before you do anything else, backup the 1st Word disk. 

Viewing the User Guide 


-MORE- 


When the words- END OF FILE -appear on the screen, press 

any key to return to the Desktop. If there is no immediate end to the data file 
being observed, press <Control> and <C> at the same time to stop the 
display. The disk directory should reappear on your screen. 


51 




Abacus 


Atari ST for Beginners 


2.7 The keyboard 


You're probably getting anxious to start programming. Let's have a close 
look at the keyboard first. 

You'll remember that the ST can communicate in different programming 
languages such as BASIC, LOGO and C. However, these programming 
languages are not built into the ST. We have to load these languages from 
the Language Diskette. 

Insert the Language Diskette in a disk drive, double-click the disk drive 
icon, then double-click the BASIC .PRG icon. The screen displays four 
windows. We'll use these to test the ST keyboard. 

Most ST keys are not used with every program since the ST can function 
without the keyboard. This is why the mouse, icons and drop-down menus 
exist. 

Once BASIC is loaded, we can enter data from the keyboard. The entries 
appear in the command window at the bottom left. 

Your ST keyboard has four sections: 

1) QWERTY typewriter keyboard 

2) function keys 

3) editing keys 

4) numeric keypad 


2.7.1 Typewriter keyboard 


Here you have all the upper and lower case letters of the alphabet, as well as 
many special symbols. Upper case letters are entered by pressing <Shift> 
and the desired letter. Like a typewriter, there are special keys to perform 
different functions. 


52 



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Atari ST for Beginners 


2.7.1.1 <Alternate> 

Pressing <Altemate> in conjunction with other keys including <Shift> 
<Altemate> allows ST users in different countries to access the special 
characters required by their language not found on a normal QWERTY 
keyboard. This gives them special characters such as a or R, normally not 
accessible. Programmers can also take advantage of these keys. A 
programmer could increase the number of the function key functions from 
10 to 30 by using the <Altemate> and <ShiftxAltemate> keys. 


2.7.1.2 <Control> 

Some of the keys are used in conjunction with the <Control> key to 
perform special functions. For example, a <ControlxC> in LOGO or 
<ControlxG> in BASIC stops a program during execution. 


2.7.1.3 <Shift> 

Pressing a letter key while holding down <Shift> displays the upper case 
letter, or the character that appears on the upper half of the key (i.e., 
<Shift><3> will print a 


2.7.1.4 <Caps Lock> 

The <Caps Lock> key is essentially an on/off switch. Press it once to type 
upper case letters without having to hold the <Shift> key. Press <Caps 
Lock> a second time and the keyboard returns to its normal lower case 
mode. 


2.7.1.5 <Tab> 

The <Tab> key is a tabulator, which moves the cursor a specified number 
of spaces to the right in certain application programs. The cursor is shown 
as either a block or vertical line. <Tab> is handy for formatting numbers or 
text. 


53 



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2.7.1.6 <Esc> 

<Esc> (Escape) is similar to <Backspace> in many programs. It returns you 
to the main menu in some word processing programs. In other programs, 
<Esc> frequently serves as a program interrupt. 

GEM uses the <Esc> key for two functions. First, you may update a disk 
directory when you switch diskettes by pressing <Esc>. Second, you can 
change a disk name in Info by pressing the <Esc> key to erase the old 
name. 


2.7.1.7 <Backspace> 

This key moves the cursor one space to the left, erasing the character to the 
left. Holding the key down will repeat the action (i.e., the cursor will 
continue moving to the left until the key is released). 


2.7.1.8 <Delete> 

The <Delete> key erases the character on which the cursor rests. <Delete> 
and <Backspace> have the same functions in most programs. 


2.7.1.9 <Return> 

The <Retum> key has its origins in the days of the typewriter, when the 
return lever performed a carriage return and line feed. Even if you aren't 
using a printer, the ST still displays data on the screen. Pressing <Retum> 
advances the cursor one line down, and to the left margin of the next line. 
Languages such as BASIC use <Retum> to enter the current program line. 

The <Enter> key often has the same function as <Retum>. Both keys are 
called data entry keys in this book. 

GEM uses <Retum> to confirm dialog box information, if you prefer to 
input through the keyboard instead of the mouse. When a dialog box gives 
you two choices, such as OK or Cancel, you will notice that the border of 
one of the buttons is wider than the other. Pressing the <Retum> key is the 
same as selecting the enlarged button. 


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I .OK I I Cancel I 


FLOPPV DISKyFLOPPV DISK 


Desk File View Options 


306351 bytes used in 3 itens. 


CONTROL.ACC EMULATOR.ACC BASIC.PRO LOGO.PRO NEO.PRQ 


DELETE FOLDERS / ITEMS 


Folders to Delete! 0 

Itens to Delete! _1 


Press <Retum> to cancel 



Data entry keys — <Retum> and <Enter> 


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2.7.2 The function keys 


The function keys are the diamond-shaped keys that run across the top of 
your ST, and are numbered <F1> to <F10>. They can be programmed for 
different commands or characters. For example, <F2> might be used in a 
game to specify the level of difficulty, or <F1> might load data into a 
database. Uses for function keys are limited only by the programmer's 
preference. 


2.7.3 Editing keys 

The editing keys are at the right of the typewriter keyboard: 

2.7.3.1 Cursor keys (<-»><T>«-><i>) 

The cursor keys move the cursor in the direction of their marked arrows. 


2.7.3.2 <ShiftxAlternate> cursor keys 

You can move the mouse pointer using these combinations. Cursor keys 
with <Altemate> move the pointer eight pixels in the desired direction, 
while <ShiftxAltemate> cursor keys move the pointer one pixel at a time. 


2.7.3.3 <Insert> 

<Insert> allows you to insert words, text, etc., into already existing text. 
<Insert> toggles on and off. Pressing the key once causes the cursor to 
move to the right when typing in new text, and pressing it again turns off 
the insert feature. 


2.7.3.4 <Clr/Home> 

<Clr/Home> has a double function in some programs. Pressing this key 
sends the cursor to the "home" area (the upper left comer of the screen). A 
<ShiftxClr/Home> clears the screen completely. 


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2.7.3.5 <Help> 

This key often does just what its name implies. If you don't know what to 
do next, press <Help> for advice. 


2.7.3.6 <Undo> 

We read about <Undo> earlier when reading about the VT52 emulator. As 
the name suggests, <Undo> undoes (cancels) the previous entry. 


2.7.3.7 <AlternatexHelp> 

<AltematexHelp> sends a "snapshot" of your screen to a properly- 
connected printer (as discussed in section 2.3.2.4). Pressing 
<AltematexHelp> a second time turns off the screen dump. 

Note: If you don't have a printer connected, your ST may crash (stop 
operating) when you press <AltematexHelp>. The only way out of a 
crash is to press the reset button in the back, or switch the system off and 
on again. 


2.7.4 Numeric keypad 
2.7.4.1 <Enter> 

The <Enter> key has the same function as <Retum>, as mentioned above. 


2.7.4.2 Numbers, math symbols and decimal point 

The ten digits and arithmetic symbols are the same as those on the top row 
of the keyboard, except the keypad has them arranged in the standard 
keypunch format for single-handed use. 


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Chapter 3 


( 


\ 


ST BASIC 


V 


_/ 















































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Atari ST for Beginners 


ST BASIC 


This chapter will introduce you to the BASIC programming language. 
BASIC stands for Beginner's All-purpose Symbolic Instruction Code. All 
we'll do here is familiarize you with some commands, help you write a few 
simple programs, and give you some hints on larger programs. Once you 
understand the essentials of BASIC, you should read other books on the 
language, such as the ATARI ST BASIC Training Guide from Abacus. 


3.1 How the ST understands BASIC 


3.1.1 What is BASIC? 


Up until now, all we have done with our ST is answer questions and 
respond to commands. Now it's time for some real dialogue between you 
and your computer. To communicate, both parties must be able to speak the 
same language. The ST understands several languages—but these are 
programming languages, not French or German. 

The Language Diskette contains everything the ST needs to be able to 
understand a language. This diskette contains the vocabularies and the 
grammar (or syntax) of two languages—BASIC and LOGO. 

Once one of these languages is loaded into the ST's memory, you can use 
the keyboard to communicate with the ST. We'll start with BASIC. 


3.1.2 Loading BASIC 


Insert the Language Diskette into drive A. Simply open the directory of that 
diskette by clicking the drive's icon, then double-click the BASIC. PRG 
icon. 


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3.2 Windows in BASIC 


3.2.1 How windows work in BASIC 

BASIC has altered the look of our screen considerably. The menu line at the 
top displays terms that are familiar to us, but four new windows appear: 

• The OUTPUT window displays the program 

• The COMMAND window accepts program data 

• The LIST window lists the program code 

• The EDIT window is used to edit the program 

The COMMAND window can be used to call up the other windows. Type 
List on the keyboard and press the <Retum> key. The LIST window 
appears after a brief time. 



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The EDIT window can be seen in the center of the screen and behind the 
other three windows. Move the pointer to that window, click it, and the 
EDIT window will become the top window. 



3.2.2 Changing ST BASIC windows 


Before we start BASIC programming, play around with these four 
windows, placing them in different arrangements on the screen. You can 
move them around and change their sizes, as you did with the disk 
directories. 


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3.3 Beginning with BASIC 


3.3.1 Direct mode 


Let's communicate with ST BASIC. If you haven't yet double-clicked the 
ST BASIC program icon, please do so. 

Type in ST. The COMMAND window will display the letters ST following 
the statement OK. If you type in any other text, the letters will appear in the 
COMMAND window. 

To let the ST know that we want to do something, we must end any BASIC 
input by pressing the <Retum> or <Enter> key. So after you type ST, press 
<Retum>. 

The ST responds with the message Something is wrong. This means 
that the ST has received your message—it just doesn't know what it means. 
Although this Atari computer is called an ST, the ST name is not a part of its 
BASIC vocabulary. 


Desk File Run Edit Debug 


LIST 

OUTPUT 








s 



o 


Ok ST 

A 

Sonething is wong 


Ok I 0 



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If you try to type in other words or phrases, the response will be the same: 
The text, an error message, and OK. The OK indicates that the ST is ready 
for more data. 

Let's try something else. Enter the following command: 

PRINT "atari st" <Retum> 

You should see atari st displayed in the OUTPUT window. 

This output was initiated by the PRINT command, which is. in the ST 
BASIC vocabulary. You can put anything between those quotes instead of 
atari st: your name, your mother's name, the first line of War and 
Peace , etc. The ST executes your command when you press <Retum>. 

This procedure is called direct input. Executing commands outside of a 
program is called direct mode. 


3.3.2 Program mode 


Direct mode requires you to constantly type in line after line. If we want to 
execute a number of tasks, we have to write a program. 

BASIC was invented for programming. Once you write and enter a 
program, tasks can be carried out as often as you desire, started with a 
single command. This is program mode. 

Let's see how we can get the ST to work for us, using the most important 
BASIC commands and techniques. For example, clear (erase) the second 
window (OUTPUT) by typing the following line. (If you make an error, 
<Backspace> over the mistake and retype it): 

clearw 2 

clear = clear 
w = window 

2 = window number 

clearw 3 clears the COMMAND window. 


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3.4 The BASIC vocabulary 


3.4.1 print and input 


3.4.1.1 Line numbers 

Each line in ST BASIC must have a line number. Do not type in a command 
after OK —start with a number. The best way to do it is to start with 10 and 
increase by steps of 10 (10, 20, 30, etc.). This gives you extra space for 
inserting other lines as they are needed (15, 17, etc.). 

The BASIC command or commands follow the line number. 


3.4.1.2 PRINT 

As we have already seen, PRINT writes characters, known as a string, on 
the screen. Let's use our earlier example in a program line: 

10 PRINT "Atari ST" 

If you make an error, <Backspace> over the mistake and retype it. Press 
<Retum> to enter the line. 

Our program is now in memory, but has to be executed. BASIC programs 
are started with RUN. You can enter this command in direct mode, or click 
Run from the menu bar. The program then runs— Atari ST appears on 
the screen in the output window. We have the same result as before, with an 
important difference: Direct mode is typed in directly, while 
programs require line numbers. 


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3.4.1.3 INPUT 



Clear the OUTPUT and COMMAND windows by typing clearw 2 and 
clearw 3 in the COMMAND window. Our one-line program is in 
memory, but is invisible for now. Clear the program from memory by 
typing the direct command NEW. Now we want the ST to print what is 
between quotes, and then wait for input from the keyboard. We can input 
text in a program with INPUT: 

10 input "What should I write?"/ a$ 

20 print a$ 

Now click Run. The ST asks you What should I write?. Answer 
by typing in some text. Press <Retum> to see this text. 

Line 10 prints the question and a question mark on the screen. This is done 
by using the INPUT statement, which expects a response. Your response is 
stored as a variable called a$. The dollar sign signifies that the answer was 
in the form of text. 


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We would have to remove the dollar sign to accept numeric values. Line 20 
displays the contents of a$ (your entered text). The program ends, and OK 
appears in the COMMAND window. 

Remember: the INPUT command relates a variable to a string or number. 
PRINT displays the variable contents. 


3.4.2 GOTO 



Erase program memory with NEW, and clear the three windows with 
clearw 1, clearw 2 and clearw 3. 

One of the simplest programs consists of two lines. Enter these lines on 
your ST: 


10 print "ST"; 
20 goto 10 


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Now RUN this program. The string ST appears again and again. This will 
continue until the power is turned off, the reset button is pressed, or the 
<ControlxG> key combination is pressed. A message will appear on the 
screen: Break at line xx. The program can be continued by typing 
CONT (CONTinue). 

Line 10 PRINT displays ST on the screen. The semicolon at the end of 
the line causes the STs to be printed right next to each other. 
Line 20 GOTOl 0 returns the program to line 10 (an infinite loop). 


LIST 

OUTPUT 




STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 

STSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTSTS 







^ CntttflHD 


". 

Ok ZO GOTO 10 

Ok RUM 


0 

— Break -- at line 20 

Br 1 


0 

-h • '~n- 



* 


GOTO causes the program to jump to the specified line number. 


3.4.3 IF. .THEN. .ELSE 


GOTO is executed without any special requirements. An IF . .THEN 
statement can initiate a jump, but only after certain prerequisites are (or are 
not) fulfilled. Erase the ST's program memory by typing NEW and clear the 


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three BASIC windows as you did above, then enter the following program. 
If you make an error, <Backspace> over the mistake and retype it. Don’t 
forget to press <Retum> after each line. 

10 input "1st number";zl 

20 input "2nd number";z2 

30 if zl=z2 then 60 else 40 

40 print "The numbers are not the same." 

50 goto 70 

60 print"The numbers are equal." 

70 end 

Now RUN the program. You will be asked to enter the first number. Enter 
any number and press <Retum>. The program stores the value of this 
number in the numeric variable called zl. A second number is then 
requested by the ST. Enter another number and press <Retum>. This value 
is stored in the numeric variable called z2. The ST determines whether the 
two numbers are equal or not. 

We've seen lines 10 and 20 before. Our variables here are zl and z2. 

Line 30 checks for equality between zl and z2. There are two possible 
courses of action for the program: 

1) If the numbers are equal, the ST goes to line 60 
and declares that variables zl and z2 are equal, 
then the program ends at line 70. 

2) If the numbers are unequal, the ST goes to line 
40. The IF...THEN...ELSE command states that 
IF something is fulfilled THEN a jump to the 
stated line occurs, or ELSE the alternate line 
number is executed. IF zl=z2 THEN go to 
line 60; or else, go to line 40, which states that 
zl and z2 are different. The program then goes 
to line 70, and the program ends. 

Remember: IF...THEN...ELSE "jumps" to other parts of the program under 
certain conditions. 


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3.4.4 FOR...NEXT loops 

You can write a program that counts while running, then stops at a 
predetermined number. To accomplish this, you need to write a loop. We 
can start with the same program presently in memory. Do not type NEW, but 
erase the three windows with clearw. Then enter the following four lines: 

5 input "How many times";d 

6 for i=l to d 

70 next i 

80 end 

To check how a program looks before you RUN it, move the mouse pointer 
to the drop-down menu Edit and click List. Each line of the program 
appears in the LIST window: 

5 input "How many times"; d 

6 for i=l to d 

10 input "1st number";zl 

20 input "2nd number";z2 

30 if zl=z2 then 60 else 40 

40 print "The numbers are not equal." 

50 goto 70 

60 print "The numbers are equal." 

70 next i 

80 end 

We added lines 5 and 6 to the program. We changed line 70 as well: the ST 
erased the old line 70 and put the new line 70 into memory. Previously line 
70 was simply: 

7 0 end 

Line 70 now reads: 

70 next i 

We also added line 80. See how simple it is to edit the programs? You only 
have to enter the new information. The rest of the text does not have to be 
retyped, because it is still in memory. 


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What did we change? Line 5 is obvious. The variable d has the value of the 
number, indicating how many times the program has to run through. Then 
line 6 follows. Here is the beginning of the loop. The end of the loop is 
found in line 70. Everything in between belongs to the loop. 

Let's follow the program: 

Line 5: Number of times in variable d. 

Line 6: Begin loop. The variable i (also called the counter) is raised 

by the value 1. Then the ST checks to see if i equals d. 

Lines 10 to 60: Program like the one you wrote earlier. 

Line 70: Jump to the beginning of the loop (line 6). There i is again 

raised by 1 and i is compared for equality to d. If this is not 
the case, the loop is performed until i equals d. When this 
occurs, the program jumps to line 80 (end of the program). 


3.4.5 GOSUB...RETURN 


GOSUB is an abbreviation for GOto SUBroutine. Subroutines are 
program segments that are called repeatedly. The main difference between 
GOTO and GOSUB is that GOSUB requires a statement to a) mark the end of 
the subroutine, and b) send the system back to the main program from 
which the GOSUB occurred. In reference to our two-line program, this 
would mean that the screen output of the string atari st is a subroutine, 
limited by the main program: 


10 gosub 100 
20 goto 10 
100 print "ST"; 
110 return 


The RETURN command in line 110 causes BASIC to return to the line 
following the GOSUB, and program execution continues from line 20. 

Maybe we haven't clearly defined the subroutine here. But in Section 3.9, 
we'll see how well subroutines facilitate program control. 


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3.4.6 REM statements 


If you type the word REM (abbreviation for REMark) at the beginning of a 
line, your ST ignores this line and continues with the next. We can enter 
comments following the REM which remind us and inform others of how 
the program operates. This is especially valuable in longer programs. Let's 
add some REM statements to our GOSUB program: 

10 rem program for GOSUB demonstration 
20 rem jump to screen output subroutine 
30 gosub 100 

40 rem go back to start of program 
50 goto 10 

100 rem screen output subroutine 
110 print "atari st" 

120 return 

Before you start the program with RUN, look at the listing by clicking 
List. The advantage of using REMs is that you can read this program 
months later, yet still be able to understand what the program is doing at a 
specific line, even if you have long forgotten the program. 


Desk File Run Edit Debug 


LIST 

* 1..—hJ K 

10 ren progran for GOSUB denons 

ZB ren junp to screen output su 

30 gosub 100 

40 ren restart of progran 

50 goto 18 

109 ren screen output subroutine 

110 print"atari st" 

120 return 


atari st Ut 

atari st 
atari st 
atari st 
atari st 
atari st 
atari st 
atari st 
atari st 

O 




COMMAND 

Ok 100 ren screen output subroutine 

Ok 110 print"atari st" 

Ok 120 return 

Ok list 

Ok run 



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3.4.7 Clearing the screen 


3.4.7.1 Erasing the windows: clearw 

The command clearw n should be used before starting a new program. 

The letter n can be values from 0 to 3, for the four ST BASIC windows: 

n =0: Erase the EDIT window 
n =1: Erase the LIST window 
n =2: Erase the OUTPUT window 
n =3: Erase the COMMAND window 



3.4.8 NEW 

If you want to erase everything in BASIC program memory—both the 
variables and the program—use the new command. But be careful. A 
NEW command erases everything in memory. Once you give the new 
command, your program is lost forever, unless it was previously saved 
onto a diskette. 


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3.5 Variables 


You might have already noticed that programming a computer is almost 
impossible without the use of variables. Let's begin our explanation by 
discussing numeric variables. 


3.5.1 Simple numeric variables 

Your ST has to retain a lot of numbers in memory. To memorize the 
different numbers, the ST establishes a "drawer" in memory and asks you 
to name it. Until now we selected different names (a, A$, zl, etc.). For 
now we'll use the name ST, which becomes our variable name. 

Up to now, we have assigned only one value to each variable when we used 
the INPUT command. But this can be simplified by establishing an 
equation. 

For example, if we want to make our ST understand that the drawer with 
the name ST contains the number value 6, then we simply type: 

ST = 6 

Don't forget to press <Retum>. An error message does not appear in the 
COMMAND window. We know that everything is fine because the OK 
appears on the screen. Our ST remembers that the drawer called ST contains 
the value 6! 

See for yourself— print is the magic word. To display the contents of the 
drawer with the name ST, we type: 

print ST 

If you followed the instructions step by step, the OUTPUT window should 
now display the following: 


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Desk File Run Edit Debug 



Maybe you're still unsure. In the previous line you typed ST = 6. The ST 
could have done that on its own. To prove that the variable is safely in the 
ST's memory, simply clear the screen with the commands CLEARW 2 (for 
the OUTPUT window) and CLEARW 3 (for the COMMAND window). 
Then repeat the command: 

print ST 

Again the number 6 is displayed. Now that you know how this works, give 
names and number values to other drawers: 

Amanda = 4 
Brigitte = 5 
Claudia = 6 
Danielle = 7 
Rosalita = 2.1 

You can then request the ST to display these variables in the OUTPUT 
window with the PRINT command. There is enough free memory available 
in the ST to assign values for many thousands of entries. 


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A variable name may have a total of 31 characters. The first 31 characters 
are acknowledged by the ST. Any more characters are simply ignored. 

There are two more things that you should know about selecting a variable 
name: 

1. The variable name may not be a reserved BASIC word. For 
example, you can't name a variable PRINT. Try print =5 . 

The error message Something is wrong appears, since 
you've used the ST's PRINT command as a variable name. 

2. The first character of a variable name must be a letter (ST 
BASIC doesn't distinguish between upper case and lower 
case letters). 

For example, valid variable names include: A3, Ac, B, as 
well as X, Y and C. Variable names such as 4A and IE are 
not permitted. 


3.5.2 Integer and decimal variables 


Now we'll assign different kinds of numerical variables to the ST. Let’s test 
to see whether the high, multi-digit precision of the ST's computational 
output can be rounded off in order to simplify mathematical problems or 
numbers. 

For example, enter the following line in the COMMAND window: 

print 2/7 

The slash represents the division of 2 by 7. The result of the division is 
displayed in the OUTPUT window: . 2 85714. As you can see, the ST 
solved this problem to six decimal places. 

One point to remember: when a result is less than 1, the ST does not show a 
zero in front of the decimal point. Like a pocket calculator, the ST displays 
numbers less than one as a period and decimal digits. 


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How can we store this calculation in one variable? Let’s keep the name ST 
for a variable name and relate either the final result to it, digit for digit (in 
our case ST=0.285714), or enter the calculation itself: 

ST=2/7 


Now enter: 


print ST 

The following result appears in the OUTPUT window: 


Desk File Run Edit Debug 


LIST 

OUTPUT 

i, 


.285714 






- -----—• - -1 .PIilllifl 


A 

Pi 

0 


Sonething is wrong 
Ok PRINT 2/7 
Ok ST=Z/7 
Ok PRINT ST 
Ok I 


As you can imagine, a value with so many digits behind the decimal point 
requires large amounts of computer memory. 

If you're not a mathematician and only want to calculate the multiplication 
table up to 25, then it would be inefficient to waste so much memory using 
decimal numbers. Furthermore, computers calculate much faster if they do 
not work with a lot of decimal places. 


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If rounded-off numbers are acceptable for the values you use, put a percent 
symbol (%) behind the variable name: 


ST%=2/7 
print ST% 

The result in the OUTPUT window is 0. Why? Because we decided to use 
integer variables which do not retain any fractional values. 

On the other hand, if you need more than the 6 digits after the decimal point, 
enter a number symbol (#) behind the variable name: 

ST# = 2/7 
print ST# 

Result: .285714304 



However, just remember that the results beyond the sixth digit are only 
approximate with this type of calculation. 

In division problems, you should always consider which is more important: 
the amount of memory used in precise calculations, or the calculation speed. 


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The advantage of having these three different precision indicators is that we 
can then use a variable name three times. Type these in: 

print ST 
Result: .285714 

print ST% 

Result: 0 

print ST# 

Result: .285714304 

When you're working with whole numbers, or integers, remember that 
integers may be no larger than 32767 and no smaller than -32767. Integer 
variables use the percent sign (%). Otherwise the ST memorizes negative 
numbers instead of positive numbers, and vice versa. 

Finally, we can add an exclamation point (!) to the variable name. This 
symbol indicates that the calculations use simple precision math and six 
decimal places. 

The variable names ST and ST ! refer to the same figure. The variable ST! 
is marked for simple precision. 


Desk File Run Edit Debug 


LIST 

OUTPUT 



777 

60S 

666 

,285714 

,285714 

0 

,285714104 

.222222 

,222222 









1 HUB 


s. : ' coMttnHDi :c,r- 

-- = - - == - =-—== " 1 


Ok PRINT ST* 

Dk PRINT ST# 

10k ST! =2/9 

Ok PRINT ST! 




0 

Ok PRINT ST 

Ok 1 




0 

joj 



"W 

E 


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ST!=2/9 
print ST! 

Result: .222222 

print ST 

Result: .222222 

The variable ST ! corresponds with the variable ST. Therefore, the contents 
of the variable ST changes and adopts the same value as the variable ST!. 


3.5.3 String variables 


You might be surprised that we handle string variables, that is, text, 
separately from the numbers. Is it possible to store text in our existing 
variable types? Let's try it. Store the word this in the variable ST. Type 
the following: 


ST = this 

Now let’s take a look at what is in variable ST: 

print ST 

Result: 0 

This is not what we wanted. The word this was accepted by the computer 
as another variable name. Therefore, the value of the "new" ST (until 
now=0) was simply copied into our existing variable ST. In effect, the 
"new" ST also became 0. 

Remember what we said previously about the print command: if we want 
to output words or characters to the screen, we have to place the text 
between quotes. Let’s try this with variables: 

ST ="this" 


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Desk File Run Edit Debug 


new 


EDIT 


OUTPUT 


,285714 

0 

,285714304 

.285714304 


*!' | ; ; M ; m ; ; M COHHflND ; ; ' M ; : . i ! m . 



Ok ST=THIS 
Ok PRINT ST 
Ok ST^THIS" 

A 

Types of values do not natch 
Ok I 


m 


The result is a new error message: Types of values do not 
match. This means that you used the wrong variable type. The numeric 
variable ST is not an acceptable variable type for storing text. 

We need another symbol to designate a string variable: the dollar sign ($). 

If we add this symbol to a variable name, then we create a string. You can 
store up to 255 characters in a string variable. 

Type the following lines into the COMMAND window with the correct 
variable type, as a string variable: 

ST$="this" 
print ST$ 

Result: this 

You may also store numbers in a string variable. You must enclose these in 
quotes as well, or the error message Types of values do not 
match reappears. 


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You cannot directly calculate with a string variable. Try it: 


Result: 


ST$="33" 
print ST$ + ,f 11" 
3311 


Desk File Run Edit Debug 


new 

i 


EDIT 


OUTPUT 


.285714 

0 

.285714304 

.285714304 

e 

THIS 

3311 






! L-l j i i i CDHHflHD, 


HHilir: I : 


Types of values do not natch 
Ok ST$= n THIS" 

Ok PRINT ST$ 

Ok ST$="J3" 

Ok PRINT ST$+"11" 

Ok I 


I» K 


In this case the values were not added together mathematically, but placed 
side by side. The string variable ST$ with the text 33, and the entered 
string text 11 were simply merged (or concatenated) into 3311. 

We found out that text variables may only contain up to 255 characters. This 
means that we would be unable to fit all those characters of a standard 8 1/2 
x 11" page of text (which can hold about 2000 characters) into one string 
variable. However, we would be able to distribute the 2000 characters over 
at least 8 variables for storage. 


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Two more notes about numerical and string variables: 

1. If you enter the CLEAR command, all text and variable values 
are set to zero. Always put a clear command at the beginning 
of a BASIC program. 

2. We learned that three different number values per variable name 
are possible. These variables can store the following types, 
depending on the final symbol of the variable name: 

%=no decimal point (integer) 

! = 6 decimals = real number (simple precision) 

#= with 9 decimals = double precision 
$= string (text) 

If you give a new value to an already existing variable name, the 
old value is erased. Remember: For a variable name, your ST 
only remembers the number value most recently entered for that 
variable. 



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3.5.4 Dimensioning variables 



Up to this point we have learned about double precision, simple precision, 
integer and string variables. An important command is used in conjunction 
with these types of variables—the dimensioning command DIM. 

A DIM statement allows us to use the same variable name several times with 
different values. A dimensioned variable is always signified by using an 
index. 

This index number is appended to the variable name in parentheses after 
DIM and the variable name. DIM ST(1000) entered at the beginning of 
the program means that there are 1000 different variables with the name ST. 
The variable ST can be indexed with different number values: ST (1) , 
ST (2) . . .ST (1000). 

The advantage of this method is that we don't always have to look for new 
variable names for certain program functions—we can retain the name of the 
original variable. Certain variable contents in a program could be called 


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repeatedly without having to redefine a variable name. For example, you 
could use a variable for the index figure, which you might increment (raise) 
with the help of a FOR...NEXT loop. 

In this example we can display all 100 names to be stored: 

10 dim st$ (100) 


100 for n = 1 to 100 
110 print st$ (n) 

120 next n 


Provided we had 100 names stored in the dimensioned variable ST$, then 
the above four lines would be enough for our purposes. 

Without dimensioning, we would have had to express all 100 variables 
individually in the program. This would take a long time to run, and be 
more prone to errors: 


10 print ST 
20 print ST1$ 
30 print ST2$ 
...etc. 


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3.6 ST BASIC graphic commands 


We now know the most important BASIC commands. Before we move on 
to larger programs, here are some interesting graphic commands with which 
you should be familiar. 


3.6.1 CIRCLE A, B, C, D, E 


This command draws a circle in the OUTPUT window. A indicates the X 
coordinate in pixels (the left border of the screen is 0) and B is the Y 
coordinate in pixels (the top of the screen is 0) of the circle's center. C gives 
the radius of the circle in pixels. The pixel counts vary with the screen 
resolution being used, as well as the size of the OUTPUT window. D and E 
state the beginning and ending angles of an arc in tenths of a degree: 


Desk File Run Edit Debug 


LIST 

OUTPUT 

* 






Ok tlearn 2 

Ok circle 88,8B,6B 

Dk circle 80,88,40,0,1800 

Ok circle 8B,8B,2B,96B,18BB 

Ok 1 o 



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3.6.2 ELLIPSE A, B, C, D, E, F 


This command draws an ellipse in the OUTPUT window. A indicates the X 
coordinate of the ellipse's center in pixels (the left border of the screen is 0) 
and B indicates the Y coordinate of the ellipse's center in pixels (the top 
border of the screen is 0). C is the X coordinate of the radius in pixels and D 
is the Y coordinate of the radius in pixels. E and F are the beginning and 
ending angles of the ellipse respectively in tenths of a degree. The pixel 
counts for the X and Y coordinates depend upon the resolution being used 
as well as the size of the OUTPUT window. 


Desk File Run Edit Debug 



3.6.3 OPENW n 


This command opens individual BASIC windows. The allowable values for 
n listed below also apply to CLEARW, FULLW and CLOSEW: 

0=EDIT window 
1=LIST window 
2=OUTPUT window 
3= COMMAND window 


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3.6.4 CLOSEW n 


This command is used for closing individual windows: 

0=EDIT window 
1=LIST window 
2=OUTPUT window 
3=COMMAND window 


3.6.5. FULLW n 


This command opens individual BASIC windows to full screen size: 

0=EDIT window 
1=LIST window 
2=OUTPUT window 
3= COMMAND window 


3.6.6 GOTOXY A,B 


Positions the text cursor at screen coordinates A, B. A is the column position 
of the coordinates, and B is the row position. These numbers change with 
screen resolution. 


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3.6.7 LINEF A, B, C, D 


Draws a line in the OUTPUT window from coordinates A, B to C, D. A is 
the X coordinate of the starting point of the line in pixels and B is the Y 
coordinate of the starting point of the line in pixels. C is the X coordinate of 
the endpoint of the line in pixels and D is the Y coordinate of the endpoint of 
the line in pixels. 


LIST 

OUTPUT 



V 




WM . . 1 

Ok linef 80,80420,120 

Ok linef 100,100,160,110 

oki 



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Atari ST for Beginners 


3.6.8 PCIRCLE A, B, C, D, E 


Draws a circle in the OUTPUT window. The A and B indicate the X and Y 
coordinates, C determines the radius of the circle and D and E indicate the 
beginning and the end angles (in tenths of a degree) of the circle. Circles 
and circle sections are filled in with the COLOR command (COLOR text 
color, fill color, line color, Index, style). 


Desk File Run Edit Debug 


LIST 

OUTPUT 



i 

1 





Ok color 1,1,1,8,1 

Ok pcirde 80,80,40 

Ok color 1,1,1,6,3 

Ok pcirde 88,140,40,0,1880 

0k I 0 

IP * 


3.6.9 PELLIPSE A, B, C, D, E, F 


This command draws an ellipse in the OUTPUT window, where A and B 
mark the X / Y coordinate of the X radius, C and D determine the Y radius, 
and the E and F indicate the beginning and the end angles (in tenths of a 
degree) of the ellipse. Both the ellipse and ellipse section are filled in with 
the predetermined COLOR (see 3.6.8.). 


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3.7 Useful BASIC tips 


3.7.1 Programmer's aids 


The following commands can be valuable to you when you're programming 
in BASIC. They are entered in direct mode (without line numbers) in the 
COMMAND window. 

AUTO 

This command generates automatic line numbering, i.e., you don't have to 
type in line numbers yourself. The next line number will automatically 
appear as soon as you press <Retum> at the end of entering the program 
line which you just typed. If you put a number after the AUTO command, 
this figure becomes the first line number of the program. For example, 
AUTO 100 gives you a starting line number of 100. In addition, if you add 
a comma and another number, these values are interpreted as the distance 
between lines. Pressing the key combination <ControlxG> switches the 
AUTO command off. 

DELETE 

Erases program lines. You may erase an individual line (for example, 
DELETE 2 0 erases line 20) or a larger number of lines (DELETE 10-100 
erases all lines between and including 10 and 100). DELETE -20 erases all 
program lines from the beginning of the program up to line 20. 

LIST 

Lists a program. By adding a line number to the LIST command, you can 
display a specific line on the screen. For example, LIST 10 displays only 
line 10. LIST 10-100 displays lines 10 to 100, inclusive. 

RENUM 

Renumbers lines in memory. This command can be expanded for three 
values (parameters). RENUM 10,100,5 will renumber the program, 
beginning with the original line 10, change this line to line number 100, and 
then increment the line numbers by 5. 


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3.7.2 Debugging 


Here's a quick look at ST BASIC's aids for debugging (fixing errors): 

1. You can stop a running program by pressing <ControlxG>. 

The program may be continued by typing CONT and pressing 
<Retum> or <Enter>. 

2. You can stop a running program by pressing <ControlxC> (no 
continuation is possible). 

3. TRON lets you trace the program line by line as it's running 
(indicates line numbers only). TRON is disabled by TROFF. 

4. The TRACE command also allows you to trace the program line 
by line as it's running. Unlike TRON, TRACE displays the entire 
program line, including the line number. TRACE is disabled by 

UNTRACE. 

5. FOLLOW A tells you the current value of the variable A. 

The commands TRACE, UNTRACE, TRON and TROFF can be selected from 
the Debug menu. You may also enter these commands from the keyboard. 


Desk File Run Edit 

LIST 



? IB print"ABACUS":gotolfl 


IQUTPUTi 


ABACUS 

ABACUS 

ABACUS 

ABACUS 

ABACUS 

ABACUS 

ABACUS 

ABACUS 

ABACUS 


0 


o| l ;•••: 

K 

COMMAND 

Ok run 





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3.7.3 The edit window 


The EDIT window lets you freely revise and correct your program. You 
call the EDIT window and Edit mode either by typing EDIT in the 
COMMAND window, or by clicking Start Edit in the Edit menu. 

For example, typing EDIT 20 displays line 20 in the EDIT window: 


Desk File Run 

L 


Debug 


Start Edit 

Exit Edit 


OUTPUT 


Pksta Line .> 
Delete Lines 
Insert Space 
Delete Char 
Insert Line 
Reaoye Line 


Page Up 
Page Dow? 


Load Text 



Ok edit 
Ok EDIT 77 
Ok I 

Oi 




± 

E 


Here is the command set in Edit mode: 

Start Edit 
Exit Edit 
Help Edit 
Goto Line... (#) 

Delete Lines 
Insert Space 
Delete Char 
Insert Line 
Remove Line 

Page Up (in the listing) 


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Page Down (in the listing) 

Load Text 
Save Text 
New Buffer 
List 

Furthermore, you can do some editing with the function keys. Clicking the 
option Help Edit in the Edit menu displays the function key layout. 



Editing is very simple. After selecting the EDIT window, you find the 
program listed there. Now you can correct the program line by line. The 
edited text is always listed in grey. Before confirming the changed line with 
the <Retum> key, you can look at your work, store it (Save text) and 
also process it using the function keys listed above. 

Now try writing a small program and experiment with editing a little. You'll 
see how easy it is to write programs on die ST. 


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3.8 Working with the disk drive in BASIC 


Before you use a blank diskette, you must format it using the Format- 
program in the Desktop. You can save programming languages and your 
own programs on formatted diskettes. The drop-down menu File has 
everything you need. Have you entered a program that you want to use 
again? Then let's open the File menu: 



3.8.1 Load and Save As 


Do you have a formatted diskette ready? Insert it in the drive and then click 
Save As. Now enter a name for our program. For example, type TEST1; 
the name appears below the word Selection : in the file selector dialog 
box. Click OK. Your program is now stored on the diskette for later 
retrieval. 

Now we'll load the file we just saved. Your program name can be seen to 
the left in the item selector dialog box. 


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Select your program with the mouse, and click it. The filename appears in 
the Selection: field. When you click the OK button, the program is 
loaded into memory. 



3.8.2 Delete File, Merge and Quit 


We can erase a previously saved program from diskette with Delete 
File. This function is equivalent to moving a file icon to the trash can. If 
you select the Delete File option, the item selector dialog box is again 
displayed. Click the file you want to erase. The filename then is displayed 
below Selection :. It is deleted after you click OK. 

Note: Be careful with this command—the Delete File 
option erases the file permanently!! 

Merge lets you combine a program on diskette with another program 
already in memory. Again, be careful with this command!! Once the 
merge is performed, the two original programs are merged in memory, and 
only one remains—the merged program. 


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Merge is very useful for combining small program sections to create one 
large program. But be sure to renumber the programs to fit consecutively 
before you perform this command, or else things can get confusing. For 
example, Program 1 contains the line numbers from 10 to 150. You should 
renumber the second program so that it begins with line 160. Otherwise 
you 11 get a mixture of line numbers which is difficult to unscramble. 

The Quit option exits BASIC and returns you to the GEM Desktop. 

We now know some of the most important commands of ST BASIC. Of 
course, space prohibits our detailing all of ST BASIC's commands. If you 
are interested in learning more about BASIC programming, you should 
consult a book on the subject, such as the ATARI ST BASIC Training 
Guide from Abacus. 


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3.9 First programs 


Beginning computer users often try to deal with long program listings 
without any previous knowledge of BASIC. It's not surprising that finding 
errors is almost impossible, since no one is immune from making 
typographical errors. And computers do not overlook even the slightest 
typographical error. 

You'll find BASIC programs on the following pages which contain the 
whole vocabulary introduced in this chapter. A detailed explanation of the 
program lines follows each program listing. 

In some places you'll find commands that you haven't yet seen in this book. 
In these cases, the explanatory text should clarify things. 

Now two hints: 

• When you enter the following programs into your ST, don't 
forget to press the <Retum> key at the end of each line. 

• You can skip REM lines in the program explanations, since they 
are simply there for your reference. 


3.9.1 Telephone book 


This program lets you use your ST as a telephone directory. First enter the 
number of names you want in your directory, then the names and telephone 
numbers. When you run the program, simply enter a name into the ST. The 
program will find you the correct telephone number for that person. 

10 REM Telephone book 
20 CLEARW 2 

30 INPUT "How many telephone numbers";A 
40 REM dimensioning for numbers and names 
50 DIM NA$(A), NU$ (A) 

60 CLEARW 2 

70 REM telephone listing 
80 FOR N=1 TO A 
90 INPUT "Name"; NA$ (N) 


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100 INPUT "Number"; NU$ (N) 

110 PRINT 
120 NEXT N 

130 REM Search for Telephone numbers 
140 CLEARW 2 

150 INPUT "Which number are you looking for";A$ 
160 FOR N=1 TO A 

170 REM Found name; print the number 
180 IF A$=NA$ (N) Then GOSUB 210 
190 NEXT N 
200 GOTO 140 

210 REM subroutine: Print the number 

220 PRINT "The telephone number: "; NU$ (N) 

230 PRINT 

240 INPUT "Please press <Return>";B$ 

250 RETURN 


Now let's look at the program line by line: 


Line 20: Erases the OUTPUT window. 


Line 30: Variable A stores the quantity of names and telephone 

numbers. 


Line 50: Here the variables for the telephone numbers (numerical 

variable NU$ (A) ) and the names (string variable 
NA$ (A) ) are set. Although the telephone number is a 
numerical value, we had to select a string variable due to 
the slash (i.e., 616/241-5510). 

Line 60: Erases the OUTPUT window. 


Line 70-120: Prompt for name (line 90) and his/her telephone number 
(line 100). All names are entered here according to your 
entry in variable A in line 30. Therefore, the shape of the 
FOR...NEXT loop for frequent runs of the same function 
are chosen (with differing variable contents). The 
prompting repeats until the value of variable A is 
reached. 


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Line 130-150: The program asks for the name for the person for whom 
you need a telephone number. This name is stored in 
variable A$. 


Line 160-190: The program searches for the name(s) you requested 
with a FOR...NEXT loop. If one of these names 
(NA$ (N) ) exactly matches the name(s) of the person 
you requested, the program goes to the subroutine in line 
210. However, if the search was unsuccessful, the 
program goes to line 140 and starts prompting again. 

Line 210-250: The program goes to this subroutine only when the 
variables A$ (desired name) and NA$ (N) (stored name) 
match up. In this case, the output of the desired 
telephone number is initiated in line 220. 

Line 240: This line halts the program until you press the <Retum> 

key. Otherwise the ST returns to the main program and 
erases the OUTPUT window (line 140). Without this 
line, the OUTPUT window would be cleared so fast you 
wouldn't see the telephone number displayed onscreen. 


Desk File Run Edit Debug 


LIST 

$ 1. iiMiisim },] k OUTPUT j..-r.il.i ■ i .1,J. L.k»blLr. K 

179 REM found nanej prin 
189 IF A$=NA$ (N) THEM 6 
139 NEXT N 

209 GOTO 140 

219 REM Subroutine: Prin 
229 PRINT "The telephone 
239 PRINT 

249 INPUT "Please press 
259 RETURN 

0. 

Khich mmber are you looking for? ABACUS 

The telephone nunber: 616/241-5510 

T 


«l iwmmmmmmmio r. 


COHMAHD 


Ok load A:\PHONEBK.BAS 

Ok LIST 

Ok run 





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3.9.2 Vocabulary program 



The vocabulary word? 




CORPORAL 

PUNISHMENT! 




This program turns your ST into a foreign language vocabulary trainer. 

The ST will ask you for the number of vocabulary words you want stored, 
and it will prompt you to enter the German as well as the English meaning. 
Then you select whether the ST should use the German or English 
vocabulary for questioning. The program randomly searches for a word, 
then prints the word on the screen. You respond to this by entering the 
matching word in the other language. 

You can substitute a foreign language other than German if you wish. 


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10 

REM Vocabulary 

program 

20 

CLEARW 2 


30 

INPUT "How many 

’ words"; A 

40 

DIM A$ (A) , B$ 

(A) 

50 

CLEARW 2 


60 

FOR N=1 TO A 


70 

INPUT "GERMAN MEANING";A$(N) 

80 

INPUT "ENGLISH 

MEANING";B$(N) 

90 

PRINT 



100 NEXT N 
110 CLEARW 2 
120 B$="" 

130 INPUT "GERMAN - ENGLISH (yes) "; B$ 

140 IF B$="yes" THEN GOSUB 200 ELSE GOSUB 280 
150 PRINT 
160 B$=" " 

170 INPUT "REPEAT (no)"; B$ 

180 IF B$ = "no" THEN END 

190 GOTO 110 

200 B=RND *A+1 

210 CLEARW 2 

220 PRINT A$ (B) ; 

230 AN$="" 

240 INPUT AN$ 

250 IF AN$=B$ (B) THEN PRINT "Correct!" 

260 IF AN$OB$ (B) THEN PRINT "Incorrect!" 

270 RETURN 
280 B=RND * A+l 
290 CLEARW 2 
300 PRINT B$ (B) ; 

310 AN $="" 

320 INPUT AN$ 

330 IF AN$ = A$ (B) THEN PRINT "Correct!" 

340 IF AN$ <> (B) THEN PRINT "Incorrect!" 

350 RETURN 

Now for the line-by-line description: 

Line 20: Erases the OUTPUT window 

Line 30: The program asks how many words you would like to use 

and stores them and their translations in variable A. 


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Line 40: 

Line 50: 

Line 60-100: 

Line 110-130: 

Line 140: 


Line 150-190: 


Here the number of the string variables in German (A$ (A)) 
and in English (B$ (A) ) is determined. 

Clears the OUTPUT window. 

Prompt for the German meaning (line 70) and the English 
meaning (line 80). You can use a foreign language other 
than German. The number of words is determined by your 
entry for variable A in line 30. Therefore, the number of 
cycles of the FOR...NEXT loop are chosen. The prompting 
for data takes place until the value of variable A is reached. 

After the OUTPUT window is cleared, you are asked 
whether you want to answer in German or English, and 
whether you want to be questioned in German or English. 
Your answer is stored in the string variable B$. 

This line determines to which subroutine your ST has to go. 
If you answered yes in line 130, then the ST jumps to the 
subroutine in line 190 (German-English); otherwise, the ST 
jumps to the subroutine in line 260 (English-German). 

Here again is the command IF...THEN...ELSE . Line 140 
can be translated into English as follows: If B$ = yes, 
then go to the subroutine in line 190—otherwise, go to the 
subroutine in line 260. 

There are always two possibilities for our IF...THEN 
questioning. When the IF statement is correct, the 
command immediately behind the word IF is executed. If 
this is not the case, the THEN command is carried out 
behind the word ELSE. If ELSE is missing in the IF 
command, and the statement is not true, and the program 
continues with the next program line. 

After checking the vocabulary for clarity, a blank line is 
printed on the screen (line 150) The program then asks 
whether you want to continue with more words (line 170). 
The entry determines whether the program ends (with the 
END in line 180), or continue (line 190). 


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Line 200-220: RND is another new command. RND creates a random 
number between 0 and 1. Line 200 multiplies the random 
number in such a way that all the vocabulary words have an 
equal chance for selection. After that, the screen is cleared in 
line 210, and the word is randomly selected and placed on 
the screen in line 220. The semicolon after the PRINT 
command sets your answer directly after the definition. 


Line 230-270: The program checks for a match between variables AN$ and 
B$ (B) . If they match, the answer was correct. An incorrect 
answer returns the program to its main section (line 270). 

Line 280-300: The random number is multiplied with the formula in line 
280 and incremented by 1, so that all words contained have 
an equal chance of being used. The screen is cleared in line 
290, and the random word displayed on the screen (line 
300). Again, the semicolon behind the PRINT statement 
places the answer to the question directly after the word . 

Line 310-350: The program checks to see if variables AN$ and A$ (B) 
match. If they do, the question was answered correctly. If 
the answer was incorrect, the program goes to line 350, 
then returns to the main program. 


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3.9.3 The chessboard problem 



Our third program shows how the ST can solve a large mathematical 
problem within a few seconds. The chessboard problem is based on the 
following story: 

Once upon a time, a King granted a Wise Man his choice of reward, in 
gratitude for rescuing the pensive princess' Virtue from almost certain 
Temptation. As his reward, this Wise Man asked only for a normal 
chessboard with kernels of wheat arranged on the chessboard in a special 
manner. The kernels were to be placed on the 64 squares so that the first 
square had 1 kernel, the second had two kernels, the third square had 4 
kernels, the fourth square had 8 kernels, and so on. 

At first, the King laughed at the request, since it seemed to be easily 
fulfilled. Since there were so many kernels of wheat in a bushel, what 
would one more or less matter? 


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But when the King ordered his men to fulfill the wish, he saw how many 
kernels would be required to fill the chessboard. He then had much less 
concern for his daughter's sacred Virtue, because he saw that not even his 
entire kingdom could supply such a large amount of wheat. The Wise Man 
had asked for the impossible-and much to his Chagrin, got the King's 
daughter instead. 

The Ende 

Here's a computer simulation of what all the king's men could not do: 

10 REM Chessboard problem 
20 CLEARW 2 

30 REM the chessboard has 64 squares 
40 FOR N=1 TO 64 
50 PRINT "square"; N 
60 REM power formula 
70 A=2 A (N-l) 

80 PRINT A; "Wheat kernels" 

90 REM all wheat stored in variable B 
100 B=B+A 

110 PRINT "Total"; B; "Wheat kernels" 

120 PRINT 

125 FOR 1=1 TO 500: NEXT I 
130 NEXT N 

The number of wheat kernels required is too large to count in the end. As 
the number is so large in square 63, you can imagine how big the number 
would be in square 64. Here is the line by line explanation: 

Line 20: Erases the OUTPUT window 

Line 40: Here a FOR...NEXT loop is opened to compute 64 squares. 

Line 50: This line outputs the square numbers on the screen. 

Line 70: The number of the wheat kernels per square is calculated in 
agreement with this formula. The arrow pointing upward ( A ) is 
the exponential symbol. It’s entered on the ST's keyboard by 
simultaneously pressing the <Shift> and <6> keys. 

Line 80: The number of wheat kernels on the current square is displayed. 


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Line 100: The quantity of wheat kernels is stored in variable B and the 
value of the square already filled with wheat kernels is added. 

Line 110: All wheat kernels on the chessboard are displayed. 


Desk File Run Edit Debug 


LIST 

® liiiiiiiililliliiiiliiiiiliiiliiiiiiiiiiiO U T P U T 

M 



square IB 

512 Meat kernels 

Total 1B23 wheat kernels 

square 11 

1024 Wheat kernels 

Total 2047 wheat kernels 

O 

T 



«1 WmmmmmmMl 

K 


T~M 


COMMAND 


Ok load A:\CHESSBD.BAS 
OK run 


Line 120-130: A blank line is placed on the OUTPUT window in line 120 
for clarity, while line 130 jumps back to line 40 to calculate 
step by step all 64 squares on the chessboard. There is a 
pause in line 125 due to the blank FOR...NEXT loop, so that 
we may read the output on the screen. 


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3.9.4 Lotto numbers 



This program shows you how your ST can help you win the lotto by giving 
you the correct winning numbers for the six-number as well as the 
seven-number lotto games. Like the foreign language vocabulary program, 
this program makes use of the RND command. 

(Note: Abacus Software, Inc. makes no guarantees, written, verbal or 
implied, as to the accuracy of these lucky numbers. Program void where 
prohibited). 

The program runs as follows: First you are asked whether you wish to play 
the six-number lotto (6 numbers between 1 and 49) or the seven-number 
lotto (7 numbers between 1 and 39). 

Thereafter 6 or 7 numbers are drawn. These numbers are then carefully 
compared with each other before being placed on the screen, so that no 
more than two equal numbers are used. Then the lucky numbers are 
displayed on the screen. 


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10 REM Lotto numbers 
20 CLEARW 2 

30 INPUT"Six-number LOTTO (yes)";A$ 

40 IF A$<> ,, yes" THEN GOTO 180 

50 FOR N=T TO 6 

60 A%(N)=RND*4 9+1 

70 NEXT N 

80 FOR N=1 TO 6 

90 FOR M=1 TO 6 

100 IF N=M THEN GOTO 120 

110 IF A%(N)=A%(M) THEN GOTO 50 

120 NEXT M 

130 NEXT N 

140 FOR N=1 TO 6 

150 PRINT A% (N) ; 

160 NEXT N 

165 PRINT 

170 GOTO 30 

180 FOR N=1 TO 7 

190 A%(N)=RND*39+1 

200 NEXT N 

210 FOR N=1 TO 7 

220 FOR M=1 TO 7 

230 IF N=M THEN GOTO 250 

240 IF A%(N)=A%(M)THEN GOTO 180 

250 NEXT M 

260 NEXT N 

270 FOR N=1 TO 7 

280 PRINT A% (N); 

290 NEXT N 
295 PRINT 
300 GOTO 30 


110 



Abacus 


Atari ST for Beginners 


Let's look at the program line by line: 

Line 10-30: After the screen is cleared (line 20), choose either the 
six-number lotto or seven-number lotto. Enter yes to play 
the six-number lotto. Enter something else in line 30 (i.e. 
no) to play the seven-number lotto. The program then moves 
on to the main program at line 180. 

Line 50-70: These lines create the random numbers for the six-number 
lotto. The multiplication of A% (N) by 44 occurs because 
numbers between 1 and 44 are chosen in the lottery. 

Line 80-130: All randomly selected numbers are compared in this line 
block. If two numbers are equal (line 110), new random 
numbers are produced by returning to line 50. 

Line 140-170: The six different numbers are output. Good luck! 

Line 180-200: Within these lines the seven random numbers for the 
seven-number lotto are produced. The multiplication of 
A% (N) by 40 occurs because numbers between 1 through 
40 are chosen. 


LIST 

>5 K 

230 IF N=M THEN GOTO 250 

240 IF A*CN)=AZ(H) THEN 60T0 180 
250 NEXT M 

280 NEXT M 

270 FOR N=1 TO 7 

280 PRINT flZ(N)J 

250 NEXT N 

255 PRINT 

300 GOTO 30 


IB 39 5 3B 31 11 £ 

Six-nunber LOTTO (yes)? no 

23 32 3 20 17 27 24 

Six-nunber LOTTO (yes)? no 

20 2 11 30 31 14 28 

Six-nunber LOTTO (yes)? yes 

13 34 5 15 14 32 

Six-nunber LOTTO (yes)? no 

19 25 22 23 30 9 29 _ 

Six-nunber LOTTO (yes)? 1 o 

- 



COMMAND 

Ok load O:\STBEGINS.PGS\LOTTO.BflS 

Ok list 

Ok run 



Ill 
























Abacus 


Atari ST for Beginners 


Line 210-260: In this line block, all randomly selected numbers are 
compared. If two numbers are equal (line 240) new random 
numbers are produced by returning to line 180. 

Line 270-300: Here the seven numbers are output. They may be used for 
entry on the lotto ticket, including chance digit. Good luck! 


3.9.5 Conversion program 



lXA-F £CH&CCe*JZ&e.6e‘Z 


This program actually consists of four individual subroutines. These 
subroutines demonstrate how your ST can remember conversions, for 
example, from DM (German marks) to dollars and dollars to DM; or from 
centimeters to inches and inches to centimeters. The series may be continued 
at random. 

This program starts with a menu from which all of the subroutines are 
selected by pressing <Retum>. 


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10 REM MENU 
15 CLEARW 2 

20 PRINT "PLEASE CHOOSE ONE:" 

30 PRINT"1 CONVERT DM TO DOLLARS" 

40 PRINT"2 CONVERT DOLLARS TO DM" 

50 PRINT"3 CONVERT CM TO INCHES" 

60 PRINT"4 CONVERT INCHES TO CM" 

70 INPUT"WHICH CONVERSION WOULD YOU LIKE";X 

75 REM Jump to appropriate subroutine 

80 ON X GOTO 90,150,210,270 

90 REM DM-dollar conversion routine 

100 CLEARW 2 

110 INPUT"PLEASE INPUT DM";A 
120 B=A/2.67 

130 PRINT A;" DM IS ";B;" DOLLARS" 

140 END 

150 REM dollar-DM conversion 
160 CLEARW 2 

170 INPUT"INPUT DOLLAR VALUE";A 
180 B=A*2.67 

190 PRINT A;"DOLLARS EQUAL";B;"DM." 

200 END 

210 REM cm-inch conversion 
220 CLEARW 2 

230 INPUT"Please input cm";A 
240 B=A/2.54 

250 PRINT"THAT'S";B;"IN." 

260 END 

270 REM inch-cm conversion 
280 CLEARW 2 

290 INPUT"PLEASE INPUT INCHES";A 
300 B=A*2.54 

310 PRINT"THAT"S";B;"CM" 

320 END 

Line 10-70: This is the main menu. Figures from 1 to 4 are stored in X. 

Line 80: This new command determines if X equals 1, 2, 3 or 4. 

Depending on the value it returns to the 1st, 2nd, 3rd 
or 4th line number behind GOTO. 

Line 90-140: After the OUTPUT window is erased (line 100) the 
program asks for the DM amount desired (line 110). This 


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Atari ST for Beginners 


amount is divided by the actual dollar value—at the moment 
the dollar has the value of DM 2.67 (line 120). Next, the 
dollar value is placed in the OUTPUT window. 

Line 150-200: After the OUTPUT window is erased the program asks 
for the dollar amount desired. This amount is multiplied 
with the actual dollar value (line 180). The DM amount is 
placed on the OUTPUT window (line 190). 


Desk File Run Edit Debug 


LIST 

S liiiiimiiniMiiiniiiiiflifinlBiMmWOUTPUTgjRiililiijiiiiiis 1 1 

K 

24B 

B=A/2.54 




250 

PRINT"THAT 1 S"; B j n IH. 11 




260 

EHD 




270 

REM inch-tn conversion 




280 

CLEARM 2 


PLEASE CHOOSE ONE; 


250 

INPUT"PLEASE INPUT INCHES"; a 


1 CONVERT DM TO DOLLARS 


300 

B=A#2.54 


2 CONVERT DOLLARS TO DM 


310 

PRINT M THAT 1 S";B;"CM" 


3 CONVERT CM TO INCHES 


320 

END 


4 CONVERT INCHES TO CM 





WHICH CONVERSION MOULD YOU LIKE? 1 

"o 




K 


COMMAND 


Ok neH 

Ok load A:\CONVERT.BAS 

Ok list 

Ok run 





Line 270-320: After the screen is erased the program asks for the inch 
value desired (line 290). This value is multiplied with the 
actual inch multiplier (line 300). In line 310 the 
centimeter amount is placed on the OUTPUT window. 


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3.10 Summary of fundamental ST BASIC commands 


CLEARW n: 

Clear screen windows— n=0 : EDIT; n=l: 

LIST; n= 2 : OUTPUT; n=3:COMMAND. 

CONT: 

Program run continues after interruption by 
<ControlxG> or the STOP command. 

DIM: 

Dimensions a set of variables (array). 

END: 

End of program. After this BASIC command the 
program cannot be resumed with CONT. 

FOR...NEXT: 

Start and end of a program loop, often used to 
increment a value by 1. 

GOSUB...RETURN: 

Jump to a subroutine then return to the main program. 

GOTO: 

Jump to a specific program line. 

IF...THEN...ELSE : 

IF a condition is true, the statements following THEN 
are executed, or statements after ELSE are executed. 

INPUT: 

Accept data into an existing variable; INPUT can 
also receive screen output. 

LIST: 

Display program lines on the LIST screen. 

NEW: 

Deletes program in memory. 

PRINT: 

Prints variables and texts on the screen. 

REM: 

Comments after this command serve for information 
only, and are ignored by the computer. 

RND: 

Produces a random number between 0 and 1. 

run: 

Start the program run. 

STOP: 

Program interruption—continue with CONT. 


115 







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Chapter 4 


-. 

ST LOGO 

<_y 






















Abacus 


Atari ST for Beginners 


ST LOGO 


4.1 A comparison of LOGO and BASIC 


Now that we've learned the fundamentals of the BASIC language, we'll 
take a look at the second programming language included in the Atari ST 
package: ST LOGO. It differs from ST BASIC in the following respects: 

• LOGO programs do not use line numbers. 

• The LOGO screen of the ST is divided into only two 
windows. 

• One LOGO program is composed of several smaller 
LOGO subroutines with pre-defined names. These 
subroutines can be called up at any time. 

• Unlike BASIC, most LOGO output is displayed on the 
graphic screen, and only occasionally on the text screen. 

• Besides a square text cursor, LOGO has a triangular 
graphic cursor called the turtle. 

This chapter will simply introduce you to the important LOGO commands, 
and show you something about the program structure of ST LOGO. For 
more information, you might want to refer to a more detailed book such as 
the Atari ST LOGO User's Guide published by Abacus. 


L 




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4.2 Loading LOGO 

After the computer has been switched on and the Desktop has appeared, list 
the Language Disk's directory by double-clicking the disk drive icon. 

The Language Disk contains two LOGO programs. One is the program 
LOGO. PRG, the other a data file called LOGO. RSC: 



There may be other files on your disk that are LOGO programs, marked by 
the file extension .LOG. We won't discuss these programs now. Instead, 
we intend to get acquainted with some basic commands in this chapter. 

Load ST LOGO from your Language Disk by pointing the mouse pointer to 
LOGO. PRG and double-clicking that icon. 

The mouse pointer changes into a bee, which signals that the disk drive is 
working. After a short wait LOGO. PRG is loaded into memory from disk, 
and now waits for your first command. 


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Desk File Run Edit Settings 


ft hiBBiiBBB-DOD DIALOGUE^*** 

E 

GRAPHICS DISPLAY 

DR LOGO FOR 6EN! 

1 


A 


0 1 1 • 


K 




The screen on the left side is titled LOGO DIALOGUE. This is where 
your input (and some output) appears. The screen on the right side is called 

GRAPHICS DISPLAY. 

As you can see, the menu bar is different and reads: Desk, File, Run, 
Edit and Settings. The turtle (the triangular object) is displayed at 
the center of the GRAPHICS DISPLAY screen. 

The LOGO DIALOGUE screen greets us with the following message: 

DR LOGO FOR GEM! 

The "DR" term is a reference to the software firm Digital Research (DR), 
which developed both the GEM graphic operating system for your ST, and 
this ST version of the LOGO programming language. 


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4.3 The LOGO vocabulary 


4.3.1 PRINT 


Do you remember when we first looked at the PRINT command in ST 
BASIC? PRINT let us display text or characters on the screen, such as the 
results of mathematical problems. Let's see if this command also works in 
ST LOGO. Type PRINT "THIS IS LOGO" and press <Retum> or 
<Enter>. 



The first noticeable difference from BASIC is that, without pressing the 
<Caps Lock> key, ST LOGO prints all lettering on the screen in upper case. 

But what does the error message in the center of the screen mean? ST 
LOGO did not understand what was meant by the word "IS". In other 
words, in LOGO the PRINT command only affects the word immediately 
to the right of the quotation mark. The first word "THIS" appeared on the 
screen as a command entry. 


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How does ST LOGO handle mathematical problems and the decimal 
precision achieved? Try typing PRINT 2/7 <Retum>. 



Not only was the PRINT command correctly understood by ST LOGO, but 
the problem was precisely solved up to 6 digits behind the decimal point 
(remember the BASIC mathematical problem 2/7, and the different degrees 
of mathematical precision in Section 3.5.2?). LOGO did this in the same 
way that BASIC handles simple precision. 


4.3.2 MAKE 


Is it also possible to store variable values in the computer's memory with 
ST LOGO? Let's try it as if we were still in BASIC—type in a variable 
declaration such as LOGO=4 7, press <Retum> or <Enter> and watch what 
happens: 


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Abacus 


Atari ST for Beginners 


Desk File Run Edit Settings 


BKiiiiiiiiiiiiiiiiiiii nnn diologiie siii 

in in. ji,! j gj 

GRAPHICS DISPLAY 


DR LOGO FOR GEM! 

7PRINT "THIS IS LOGO" 



> 



THIS 

7PRIHT 2/7 

0.285714 

?L0GQ=47 







1^1 

LOGO ERROR! 





I don't knoH how to LOGO 

\ 




[11 





0 


0] — 


mi 

K 



No matter how informative ST LOGO error messages are, errors are never a 
good sign. The error here is very simple to diagnose: ST LOGO has no 
such word as "LOGO" in its collection of language elements. ST LOGO 
searched in its vocabulary for the word LOGO, and after finding no such 
word, displayed an error message. 

When you assign a value to a variable in ST LOGO, you must observe two 
rules: 


1) The assignment must begin with the word MAKE. 

2) The equal sign (=) is not correct for the assignment. The 
variable assignment in LOGO is made with a single quotation 
mark and a space. 

For example: 


MAKE "LOGO 47 

The variable can be viewed with print : (don't forget the space and 
colon characters preceding the variable name): 


PRINT :LOGO 


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Atari ST for Beginners 


Desk File Run Edit Settings 


* 111 

i ■!■ 1 i f- 10(50 DIALOGUE! "j i i BBS 5 

5 GRAPHICS DISPLAY 

DR LOGO FOR GEM! < 

7PRINT "THIS IS LOGO" 

THIS 

7PRIHT 2/7 

0.285714 

?L0G0=47 

7MAKE "LOGO 47 

7PRINT ! LOGO 

47 

7| 

A 

r 



: 



4.3.3 CS and CT 


CLEARW was the BASIC command to erase the different windows. ST 
LOGO also has commands that erase the two screens. 

CS clears the graphic screen (GRAPHICS DISPLAY) and CT deletes the 
text screen (LOGO DIALOGUE). 

Although the LOGO language excels in graphics display, it is not limited to 
graphics alone. 


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4.3.4 FORWARD, BACK, RIGHT and LEFT 


Originally LOGO was developed to acquaint young children with logical 
thinking through a simple method. Since children usually express 
themselves best with pencil and paper, the LOGO programming language 
works as graphically as possible. A cardboard turtle was used for logical 
operations. It had a pencil poked through its shell for drawing the turtle's 
movements. The logical steps could then be traced on a sheet of paper on 
the floor (move forward, turn left, etc.). These steps could also be 
performed repeatedly, like a spider spins its web. 

Look at the GRAPHICS DISPLAY. At the moment, a triangle (the 
turtle) is located in the center of the screen. How can we move this turtle? 



We move the turtle with the LOGO commands FORWARD (abbreviation FD) 
and BACK (abbreviation BK). We have to indicate the number of points 
(distance) which your turtle is to move. The same is true if we want to move 
the turtle RIGHT (abbreviation RT) or LEFT (abbreviation LT). Use the 
following command sequence to draw a square: 

FD 40 RT 90 FD 40 RT 90 FD 40 RT 90 FD 40 

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Atari ST for Beginners 


Desk File Run Edit Settings 


i m liOOO DIALOGUEM^MIBBI ! 

« GRAPHICS DISPLAY 

?FD 4B 
?RT 98 

?FD *0 1 

?RT 90 

?FD 40 

?RT 90 

?FD 40 

71 

< 

(> 

<M 

> 


0| l»i 

? 




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Atari ST for Beginners 



4.3.5 REPEAT 


You can avoid repeatedly typing in commands by using the LOGO 
command repeat. The REPEAT command functions very similarly to the 
BASIC GOTO command. 

We'll use this command to draw a second square. This second square will 
be much larger than the first: 

REPEAT 4 [FD 100 RT 90] 


128 








Abacus 


Atari ST for Beginners 


Desk File Run Edit Settings 


?FD 40 
?RT 9B 
?FD 40 
?RT 90 
?FD 40 
?RT 90 
?FD 40 
7REPEAT 

?l 


—OSO DIALOGUES! 


4 [FD 100 RT 901 


GRAPHICS DISPLAY 



This command sequence is much easier than typing in seven individual 
commands. Don’t forget to put the commands to be REPEATed in brackets 
following the REPEAT command itself. You could even put our pre-defined 
variable LOGO (=47) into the loop: 

REPEAT 4 [FD :LOGO RT 90] 


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4.3.6 TO 


The beginning of this chapter mentioned that one of the differences between 
ST LOGO and BASIC is that ST LOGO programs use several small 
subroutines instead of line numbers. 

A subroutine in ST LOGO may be shorter than a REPEAT loop. You only 
have to start the subroutine entry with the word TO and close it with END. 
Between TO subroutine name and END, you may add as many 
program steps as you like. 

The advantage of ST LOGO subroutines is that later on, individual routines 
may be directly called, or called from other subroutines by their names. 


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We'll construct two small subroutines: 

TO TEXTCLEAR 

CT 

END 

TO GRAPHICCLEAR 

CS 

END 

What happened as you typed these two LOGO subroutines, and what effect 
did these programs have? 

After you defined the TEXTCLEAR subroutine, the question mark at the 
beginning of the entry line below changed to a greater than symbol (>). This 
symbol was displayed until you entered the END command. 

The effect of these two LOGO subroutines that you can now use either the 
"real" LOGO command C S or the newly-defined command 
GRAPHICCLEAR. Both have the same result: the graphic screen is erased 
when you press <Retum>. 

This means that ST LOGO lets you create new commands for your own 
convenience, or use English words for LOGO vocabulary. 


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4.3.7 penup and pendown 



We talked briefly about the development of ST LOGO, when the 
kindergartners placed a pencil into their cardboard turtle to trace its path. But 
they could also remove this pencil from the turtle. LOGO gives us these 
same functions with the commands PENUP (do not draw) and PENDOWN 
(pen ready to draw). Both commands control the drawing capabilities of our 
turtle on the GRAPHICS DISPLAY screen. 

Let's use the commands PENUP and PENDOWN in a short program that 
draws one point on the GRAPHICS DISPLAY screen, then moves the 
pen up so that the next point remains blank so that eventually a dotted line is 
produced. Let's call this subroutine DOT: 

TO DOT 
PENDOWN 
FD 2 
PENUP 
FD 2 
END 


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Atari ST for Beginners 


You have just defined a procedure with the name DOT. Start the program by 
repeatedly typing DOT<Retum>. A dotted line appears on the screen. You 
can also use the REPEAT function to execute DOT, if you would prefer not 
to type the routine name over and over: 


Desk Fils Run Edit Settings 


$ flfjfi DlflLOBUEHliraiM 5 

! GRAPHICS DISPLAY 

DR L060 FOR EEN! < 

?T0 DOT 

>PEHD0HN 

>FD Z 

>PEHUP 

>FD 2 

>EHD 

DOT defined 
?D0T 
?D0T 
?D0T 

’REPEAT ZB [DOT] 

1 

i 

l 

A 

> 


♦1 1 !<> 1 

? 



133 























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Atari ST for Beginners 


4.4 More LOGO commands 


We'll introduce you to more ST LOGO commands in this section. The main 
purpose of these LOGO commands is to accomplish the greatest effects with 
the least amount of effort. You can insert these commands into larger LOGO 
subroutines with the help of the fundamental vocabulary you now know for 
ST LOGO. 


4.4.1 BOX 


BOX [X Y length height] 

This command draws a rectangle. Imagine that the graphic screen has an 
X-Y coordinate system, with the zeropoint in the lower left comer. The 
X-axis is horizontal and the Y-axis is vertical. Now you may set any 
starting point with two coordinates: X-axis and Y-axis. In other words, you 
set the lower left comer of the rectangle with the values X and Y. To draw a 
square, use equal values for the length and height. For example: 


Desk File Run Edit Settings 


BILOGO DIALOGUEj j 1 M- 


GRAPHICS DISPLAY 


?BQX QB IB 5B 581 
?BQX [20 26 10B 100] w 

?■ * 


A 


0 K 


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Atari ST for Beginners 


4.4.2 CIRCLE 


CIRCLE [A B C] 

With this command, you draw a circle at the X coordinate A and the Y 
coordinate B. This circle has the radius C. 



4.4.3 ELLIPSE 


ELLIPSE [A B C D] 

This ST LOGO command works similarly to CIRCLE, except that the two 
radii entered— C (X-radius) and D (Y-radius)—determine to what extent the 
ellipse will be drawn. If the C and D values are equal, a circle is drawn. 


135 



















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4.4.4 HIDETURTLE and SHOWTURTLE 

HIDETURTLE (abbreviation HT) 

SHOWTURTLE (abbreviation ST) 

HIDETURTLE erases the turtle from the GRAPHICS DISPLAY 
window. It will reappear if you enter SHOWTURTLE. However, the 
drawing functions win remain even when the turtle is invisible. 


136 















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Atari ST for Beginners 


4.4.5 FILLATTR and SETFILL 


FILLATTR 
SETFILL [A B C] 


You may fill enclosed surfaces with a pattern. Choose Graphics from the 
Settings menu and click TRUE at the Fill option dialog box. Then 
you may choose one of the many patterns available in ST LOGO. 


FILLATTR calls up the current fill color. SETFILL [A B C] lets you 
change parameters according to your own tastes. The A indicates the type of 
drawing style and can accept the values 0 to 4. The B indicates the index, 
and can accept values between 0 and 12. If you have a color monitor, you 
may choose up to 16 colors. The colors can be adjusted with the command 
SETFILL and the parameter C. 


Desk File Run Edit Settings 


?FILLflTTR 
[1 1 1] 

7CIRCLE [0 0 1001 
7SETFILL 12 2 11 
?B0X [100 100 20 20] 
2FILLATTR 
[2 2 1 ] 

I 



GRAPHICS 


Fill: 


Line: 


1 1 FALSE 


Style: 

Index: 

Color: 

Style: 

Midth: 

Color: 


02 

02 

01 

01 

01 

01 


Background: 00 



0 K 


137 














































Abacus 


Atari ST for Beginners 


4.4.6 SHUFFLE and SORT 


The SHUFFLE command randomly mixes the numbers in the square 
brackets following the command. SORT arranges the numbers in ascending 
sequence. 


4.4.7 MOUSE, nodes and TURTLEFACTS 


MOUSE informs you of the coordinates of the mouse pointer, and which of 
the two mouse buttons is being used. NODES indicates the available 
memory space (1 node=4 bytes). TURTLEFACTS informs you of the 
turtle's attributes. 


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4.5 The ST LOGO vocabulary—review 


BACK 

Move the turtle in the GRAPHICS DISPLAY 

window the indicated number of points backward. 

CS 

Clear GRAPHICS DISPLAY window. 

CT 

Clear LOGO DIALOGUE window. 

END 

End of an ST LOGO procedure introduced with TO. 


FORWARD or FD Move turtle in GRAPHICS DISPLAY window the 
specified number of points forward. 


LEFT or LT 

Rotate turtle in GRAPHICS DISPLAY the specified 
number of degrees left. 

MAKE 

Assign one value into a variable. For example, 
MAKE "A 55 gives A the value 55. 


PENDOWN or PD Drop turtle pen. Turtle now leaves a visible trail. 


PENUP or PU 

Raise pen on GRAPHICS DISPLAY turtle. The turtle 
can now be moved without drawing. 

PRINT 

Display variables and text in the LOGO DIALOGUE. If 
text in quotes after PRINT, only letters up to the first 
space are used. Variables must be preceded by a colon. 
Math problems are displayed onscreen without PRINT. 

REPEAT 

Repeat execution of the command sequence stated. For 
example: REPEAT 10 [FD 10] moves the turtle on the 
GRAPHICS DISPLAY forward 10 times, 10 points 
each time. 

RIGHT or RT 

Rotate turtle in the GRAPHICS DISPLAY window 
the specified number of degrees to the right. 

TO 

The name after TO is defined as a procedure, and has the 
same effect as a pre-defined ST LOGO command. 


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Atari ST for Beginners 


4.6 Debugging 


1) Interrupt the running program by clicking the Pause function in 
the drop-down menu Run. Continue the program run by clicking 
Continue in the same menu. 

2) Stop the running program by simultaneously pressing <Control> 
and <G> (the program cannot be continued). 

3) Click Watch in the drop-down menu Settings (confirmed 
with a check mark)—the current procedure will be displayed 
during the program run in the DEBUG INFO window. It also 
indicates to which procedure the system jumps, and how many 
jumps have already taken place between the different procedures. 
Clicking Watch again switches this DEBUG INFO window off. 

4) The TRACE command shows the procedure being carried out in 
DEBUG INFO. Click it off from the Settings menu again. 


Desk File Run Edit Settings 


LOGO DIALOGUE 


GRAPHICS DISPLAY 


7BECKER 


DEBUG INFDI 


[1] In BECKER, 

[2] Evaluating 
[11 In BECKER, 
[13 In BECKER, 
[13 In BECKER, 
[13 In BECKER, 
[13 In BECKER, 
[23 Evaluating 
[13 In BECKER, 


BECKER 
BECKER 
FD 150 
RT 90 
FD 20 
RT 77 
BECKER 
BECKER 
FD 150| 



140 


















Chapter 5 


- \ 

A lesson in hiSTory 
s_/ 













































































Abacus 


Atari ST for Beginners 


A lesson in hiSTory 


Now that you are familiar with your ST, we would like to provide you with 
some background information. We'll try to explain some of the operations 
taking place inside a computer that you didn't understand from reading the 
previous chapters. 

Furthermore, you might be interested to know how the ST was developed, 
and what else you might be able to do with this equipment in the future. We 
will discuss all of these topics and more in this chapter. 


5.1 The Computer Age 


5.1.1 The early days 


If you ever go to Munich, West Germany, visit the National Museum's 
computer history exhibit. In one comer of that display you'll find a huge 
calculator built in 1941 by the German Konrad Zuse. It was the first 
freely-programmable computer. It takes up a lot of space, and is extremely 
inefficient compared to modern computers. The low efficiency and 
enormous size of the Zuse computer are interrelated, since it was built from 
mechanical parts, rather than electronic components. 

We'll take a brief look at how the Zuse computer operates. The Zuse 
computer worked with a complex array of electromechanical parts. The 
mechanical relays retained and conveyed information on the basis of which 
components were switched on, and which were off. 

All the functions were handled by electromechanics in the Zuse computer. 
The machine made a great deal of noise due to clattering relays. There were 
numerous breakdowns with so many mechanical parts, and there were 
many more errors in calculation than with modem computers. 

Also, the programs were full of errors, which caused frequent malfunctions 
and incorrect functions—and from those came incorrect results. 


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By the way, the expression "debugging" originates from this time period. It 
means to look for and get rid of errors in a computer program. Legend has it 
that the first bug found was an actual insect—a moth stuck in the relay of a 
1940s American computer system. 



Some years later, the invention of the transistor in 1948 by American 
engineers J. Bardeen, W. H. Brattain and W. B. Shockley dramatically 
altered the future of computers. The transistor is a much smaller electronic 
unit than a relay, performing the same work but working electronically 
instead of mechanically (on/off logic is one of its responsibilities). A 
transistorized computer was quickly developed, which was considerably 
smaller than previous electromechanical computers. 

Inventors and developers continued work in this field. Finally, a process 
developed of combining a set of transistors into one small unit on a 
semiconductor using drawings of circuits. The drawings were done 
two-dimensionally—this was a definite step backward in the process of 
miniaturizing computer circuitry, and the first boards were probably a mess 
because of inaccuracies. 

Then somebody had the good sense to use photographs of circuits instead 
of drawings. Now a drawing of several square meters could be reduced to a 
size of only a few square centimeters. 


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The final product made from this photographed group of transistors was 
created through a special chemical process. The integrated circuit, or chip, 
was bom. One chip can perform tasks once assigned to many thousands of 
transistors. Pins emanate from the chip to connect it to the outside 
world—another circuit, perhaps another chip. 

Compared to relays and transistors, the chip is much faster—up to 100,000 
instmctions per second may be executed. This is possible because chip 
connections send electricity over very short distances. 

How far can integrated circuits develop? Well, one-megabyte chips, which 
will have one million transistor functions on a surface approximately the 
size of an aspirin tablet, are currently being mass-produced. The ST does 
not use these chips as of yet. However, a 520ST has sixteen 256-kilobyte 
chips that combine thousands of transistor functions onto surfaces about the 
size of a pinhead. 


5.1.2 Cashing in on chips 


Chips can be used for many applications. Depending on their purpose, they 
may be purchased preprogrammed, or ready for your own programming. 

The term memory was carried over to computer science to denote different 
storage capacities and abilities of chips. These different types of memories 
go under the following common general names: 

ROM 

PROM 

EPROM 

RAM 

ROM is an abbreviation for Read Only Memory. Programs are already 
stored in ROM, and may be run immediately. For example, your microwave 
oven lets you choose different settings and temperatures. You did not have 
to program these settings after you purchased your microwave oven, 
because they are permanently stored in ROM. 


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Your ST operating system is already in ROM. However, programming 
languages and applications must be loaded in from diskette. 



You can use and read memory in GEM and TOS, but you can't change the 
memory, which has already been set up by developers and programmers. 

In the preproduction development of computers, ROMs are not used 
immediately (the production costs would be far too high using 
incorrectly-programmed ROMs). 

Therefore, programmers use the EPROM (Erasable Programmable ROM). 
EPROMs let the user determine the structure of the program code himself, 
i.e., "bum" an EPROM (install a program). If the results are unacceptable, 
he can erase the old information under ultraviolet light. With the proper 
equipment, you may "bum" EPROMs with the ST yourself. You could 
store a self-written program on the EPROM (for example, the telephone 
directory program in this book). You would never have to load this program 
from disk—the program on an EPROM would be up and running the 
moment you turned on the computer. 

EPROMs are easily recognizable because they usually have small strips of 
paper on their top side. The size of the chip is determined by the number of 


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pins coming out of the chip. This strip of paper protects it from being erased 
or otherwise damaged. If this paper is removed and the chip is held under 
ultraviolet light, it will be erased, and then can be reprogrammed. 

The PROM is similar to the EPROM except that a PROM cannot be erased. 
Once a PROM is burned, its contents cannot be changed. The only way to 
change programming is to replace the old PROM with a newly-burned 
PROM. 

The most important chips in a computer are the RAMs. They can memorize 
all data entered, and can also immediately lose them due to the new 
command or power failure. 



RAM stands for Random Access Memory, which means that the memory 
can be directly accessed. Of course, we also have free access to ROM, but 
we cannot change ROM for our personal use, as we can with RAM. 

The RAM is our freely programmable memory. We can save our data or 
programs in RAM. But to keep a permanent copy of this data, we have to 
transfer the information from RAM to magnetic media, such as disks or 
hard disks. 


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5.1.3 It's as easy as 1, 10, 11 


The Zuse computer worked through relays which read two conditions— 
"current on" or "current off—and displayed the result by lighting 
incandescent bulbs. How can a computer work with these two conditions? 

In everyday work we use a number system of ten different figures: 

0123456789 

The lowest number is 0 to the left, and 9 at the right. Then what? You start 
again from the very beginning, but the 0 is now preceded by a 1—the 
number 10. Now the first digit 1 remains the same until after the second 
digit reaches a 9. Then again we start with 0 as the first digit, which is now 
preceded by 2 as the first digit—the number 20—and so on. 

Once both digits reach 9 (99), both digits turn 0 and they are preceded by a 
1(100). It happens in the same way with the hundreds and thousands. 

This number system (the decimal system) was chosen arbitrarily. Why do 
we work from base 10 and not base 2, or even base 20? 



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Once computers were developed, the next consideration was how it should 
learn a number system, especially the decimal system. You cannot teach the 
decimal system to the computer, as computer pioneers found out. 

Switches were developed that could differentiate more than two conditions, 
depending on the intensity of the electricity. However, the computer didn't 
always recognize the different degrees of electrical current. The result was 
incorrect computations and incorrect results. 

The final consensus was that the computer should only use on and off 
settings. Accurate system functions were almost guaranteed. A name for 
this off/on (0 and 1) mathematical system was chosen some time ago by 
mathematicians during the development of the decimal system. It is known 
as the binary system. 


How is it possible to process larger numbers with only the digits 0 and 1? 
Well, you could use all ones (1). For example, for the number 10, ten ones, 
and three hundred ones for the number 300. This is possible, but we want 
to use 0’s as well as l's. 



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Let's look at the binary system the same way as with the decimal system. 
We have two numbers which can be connected to each other with increasing 
size—0 and 1. Unlike the decimal system, 1 is our largest number. 
Therefore, once we get past counting 0, 1, the next number will be 10. In 
the binary system, this figure is not read as "ten", but as "one-zero". 

Next we raise the right digit by 1, and we get the binary number 11 
("one-one"). Again the number has reached its highest value before adding a 
left digit (similar to 99 decimal). The next number would be 100, then 101, 
110 and 111. 

The binary system may appear complicated at first, but if you proceed here 
in exactly the same way as you already do in decimal, you'll quickly catch 
on. If one digit in the decimal system surpasses its highest value (greater 
than 9), a 1 is simply added to its left 

To translate larger decimal numbers into binary numbers, we first assumed 
that we had to take the respective quantity of ones for each figure, i.e., ten 
ones for one-zero. But if we look at our sequence from 0 through 111, 
we'll find that in between we not only computed the conditions 1 and 11 but 
also quite a few more (10, 100, 101 and 110). Now let's look at a set of 
numbers in decimal and binary: 


Decimal 


Binary 


0 

1 

2 

3 

4 

5 

6 
7 


0 

1 

10 

11 

100 

101 

110 

111 


In other words, we do not need seven ones for the 7, as assumed before, 
but only three. But how you can continue this system into the tens and 
hundreds—it would take an eternity. However, a mathematical system is 
hidden within this logical system. We use exponents of 2: 


2 ^= 1 
2 A 2 = 4 
2 A 4= 16 
2 A 6 = 64 


2 A 1 = 2 
2 A 3 = 8 
2 A 5 = 32 
2 A 7 =128 


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Now we fit each binary digit into the following table: 


2 5 

=32 

II 

h- 1 

2 3 

=8 

II 

4^ N> 

PO 

2 1 

=2 

2° 

= 1 



1 

l 

0 

0 


= 

8 + 

4 + 

0 + 

0 = 


Now add according to these powers of 2. The binary number 1100 results 
in 4 powers of 2, because only the third and fourth digit contain a 1; the 
added two exponents amount to 12. A further example: 

Binary 11 l=decimal 2 A 2 + 2 A 1 + 2 A 0 = 4 + 2+ l = 7 

Maybe you can also see how you can change 255 decimal to eight binary 
numbers, and 65535 decimal to 16 binary numbers. 

It would be advantageous later on if you familiarized yourself with the 
binary system now—you'll run into this number system working with your 
ST and any other computer you might use. All computer logic is based on 
the binary number system. 

In addition to the binary system and the decimal system, there is another 
number system in which eight different conditions exist: the octal system: 

01234567 = the octal system 

Yet another number system has sixteen conditions (0-9, then A-F): the 
hexadecimal system: 

0123456789ABCDEF = hexadecimal system 

The logic of these systems functions the same as with binary and decimal. 

You'll find a set of BASIC programs and commands in the Appendix which 
will help you convert from one number system to another. 


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5.1.4 What is 512K, anyway? 


As you know, RAM is the memory in your computer in which you store 
your programs, texts, etc. If you turn off your ST, or if the electric power is 
somehow interrupted, all information in RAM disappears. (Some computers 
have a battery backup power supply for RAM, so that if the current fails, 
the computer receives the electrical current for the RAMs from a battery). 



The 520ST has 512 kilobytes (or 512K) of available memory for 
programming. The 1040 ST has twice that amount of memory. Other 
computers may have 3.5K, 64K, 128K, or 256K of available memory. 
What do these figures represent? 

The smallest measurable memory unit is the bit, the abbreviation for binary 
digit In the last section we learned that computers think in binary numbers, 
and that only two conditions are recognizable in computer logic: on and off. 
If a bit has a value of 1, that bit is on; a bit with a value of 0 is off. 

The next memory unit is a byte, which is made of eight bits combined. A 
byte handles numbers from 0 (or 00000000 in binary—note the eight digits, 
representing the eight bits) to 255 (11111111 in binary). The standard unit 
for measuring memory capacity is the kilobyte, which consists of 1024 
bytes. Broken down into its component numbers: 

1 kilobyte = 1024 bytes (x 8 [bits per byte]) = 8192 bits 

The 520ST, as mentioned earlier, has a capacity of 512K. If we do a little 
creative arithmetic, we can determine the number of bytes and bits that this 
memory occupies: 


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5.1.5 The function of the microprocessor 


We have learned to interpret our memory size, and we know what RAM and 
ROM are, but that's not quite enough. Some kind of central "brain" must 
manage the computer's memory cells and the decimal/binary conversions. 

This device is called a microprocessor. This is also called the central 
processing unit, or CPU. The CPU originally referred to the 
microprocessor only, but today the term CPU applies to RAM, ROM and 
microprocessor combined. 

The microprocessor is a chip containing not only ROM (its own machine 
language instructions), but also RAM (a number of registers which process 
and coordinate all information in the computer). The microprocessor built 
into your ST is the Motorola 68000, a very fast, efficient and widely-used 
microprocessor. 

You'll remember the last chapter, when we did calculations with zeros and 
ones, and when we mentioned writing 255 in binary with eight ones, and 
65535 with sixteen ones. The figures 1 and 0 are called bits. 

The 68000 is a 16/32-bit microprocessor, because it processes all at one 
time binary numbers up to (decimal) 65535. Many common home 
computers use 8-bit microprocessors like the Z80A found in the 
Commodore 128. The Z80A is not as efficient as the 68000, and 
considerably more difficult to program than the 68000. (The Z80 has 600 
commands, while the 68000 has only 78 commands). 

While the 68000 can process data in lengths of 16 bits (decimal 0 to 65535), 
its address bus has 24 lines (24 bits = decimal figures from 0 to 16777215). 
This makes the 512K of memory possible. If we were limited to 16 address 
lines, we could "only" access 65535 bytes. 


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512 [K] x 1024 [bytes per kilobyte] = 524,288 [bytes] 
x 8 [bits per byte] = 4,194,304 bits 

The 1040ST's memory capacity can be broken down in the same way: 

1024 [K] x 1024 [bytes per kilobyte] = 1,048,576 [bytes] 
x 8 [bits per byte] = 8,388,608 [bits] 

Although 524,288 bytes and 1,048,576 bytes are more accurate figures, the 
computer world finds "512K" or "1024K" much easier to read, write and 
say, so kilobytes are the standard for memory measurement. 

Remember, this capacity refers to the size of the RAM memory—the 
memory that we can actually use. A single character uses one byte of 
memory. This book is approximately 270,000 characters in length, so we 
would be able to comfortably fit the text of this book and a word processing 
program into the 520ST. 

Let's take this a step further. There are approximately 2000 characters on a 
standard sheet of paper—this means that about 260 pages of text would 
completely fill a 520ST. 



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Two items of interest: 

• The next generation of personal computers, such as the 
Macintosh II and Compaq 386, have 32-bit chips. A 32-bit 
microprocessor can simultaneously process numbers from 0 
up to over 4 billion, and works far more efficiently than a 
16-bit microprocessor like our 68000, which simultaneously 
addresses numbers from 0 to 65535. 

• Another part of the microprocessor you should try to become 
familiar with is the ALU—the Arithmetic Logic Unit. The 
ALU is the actual computer within the microprocessor that 
performs the mathematical operations. We communicate with 
the microprocessor through the computer and its programming 
language. Its language is nothing like BASIC and LOGO, 
which consist of commands like PRINT for writing, LIST 
for listing a program, or FORWARD for moving the turtle. 

Since BASIC and LOGO are very simple for a user to learn, 
they are called high-level programming languages. If you 
want to program the microprocessor directly, you need much 
more knowledge, since a number of commands in the 68000's 
own language are required just to perform one BASIC or 
LOGO command. People program in the microprocessor's 
language —machine language —because this language executes 
hundreds of times faster than BASIC or LOGO. 


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5.2 Peripherals, options and possibilities for the ST 


Now you know quite a lot about your ST's internals. You might have 
already thought about how to expand and improve your computer's 
performance. 

The ST has several ports that make it possible to interface with almost every 
piece of digital equipment on the market. There are also complete programs 
for the ST which you can use for word processing, data processing, games 
and more. Here are some ideas on what else you can do with your 
computer. 


5.2.1 Ready for connection 


As you already know, a computer consists of many components, including 
ROM, RAM and the microprocessor. ROM contains information that cannot 
be deleted, while RAM has memory available for programs. The 
microprocessor is the "brain" of the ST that is responsible for 
communication between RAM and ROM—and communication with the 
outside world. 

Unless the ST can accept input from you through devices like the keyboard, 
and then output meaningful information to devices like the monitor screen, 
your computer is pretty worthless. The ST features several input and output 
connections known as ports that connect other components such as modems 
and printers to your ST. These components, all controlled by the ST's 
microprocessor, are generally known as peripherals . The following pages 
will give you some ideas for interfacing peripheral devices to the ST. 


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5.2.1.1 The joystick ports 



o 0 o o o 


c o o o 


7 



JOYSTICK TOUCH TABLET PADDLE UGHTPEN MOUSE TRACKBALL 


The 520ST has two ports on its right-hand side into which you can 
interface two joysticks. The 1040ST's joystick ports are underneath the 
computer, as mentioned in Chapter 1. We can connect joysticks, paddles, 
lightpens, mice, trackballs and even a touch tablet to these ports. 

Joystick 

The joystick is probably the most easily recognized of all the devices listed 
above. Joystick movement is read from the primary directions (north, 
south, east and west), as well as directions in between (northeast, 
southeast, northwest and southwest). Put another way, joysticks are read in 
45° increments, or a total of eight directions. 

By moving the joystick in the desired direction, you move the object on the 
screen in the direction desired. You can use the joystick and fire buttons for 
an incredible array of video game software marketed for the Atari ST. Other 
interesting applications of joysticks include graphic software that lets you 
paint and draw a picture on the screen and then save it on diskette by 
pressing the fire button. We'll leave ideas for other joystick applications up 
to you. 


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Touch tablet 

The previous example suggested that the joystick can be used to paint a 
picture on the screen. This can be done more accurately with a touch tablet, 
which you connect to your ST through the joystick ports. The tablet gives 
you a workspace about the size of a large postcard. 

A touch tablet is a much more accurate way to record graphic input than a 
joystick. Although a tablet is more expensive than a joystick, it is designed 
expressly for drawing and painting. A plastic stylus is usually included with 
the tablet. You trace this stylus along the surface of the tablet, which sends 
each drawn dot to the computer. All points on the tablet are precisely read 
with sensors, and the information is transferred to your ST. 

The tablet has one or two pushbuttons available. One is usually on the 
housing of the tablet itself, the other in the stylus. Tablets which offer menu 
selections, like the touch screens on some computer terminals, are expected 
to be introduced soon. You touch the stylus to the spot where the desired 
function is located (for example, save to diskette, or select a color). 


Paddle 

The paddle is a close relative of the joystick. The paddle consists of a 
potentiometer or "knob" which you turn to guide an object. It also connects 
to the joystick ports. 

Here are two examples of how a program uses a paddle: 

• The knob is used like a steering wheel to steer a car on the 
screen. Pressing the fire button on one side of the paddle speeds 
up the car; the other button slows down the car. 

• A popular video game has a little man bouncing on a seesaw. If 
the little man hits the seesaw in the right spot, he is thrown high 
into the air, hitting a balloon in the sky with his head. The little 
man then falls back to Earth. You move the knob so that the little 
man hits the seesaw again instead of the ground. 

Both games could be played with a joystick, but that's not as practical (or as 
fun) as using paddles for the same purposes. 


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Trackball 

A trackball is a small box that contains a palm-sized, hard plastic ball. The 
ball protrudes through the top of the housing, and can easily be "rolled" in 
any direction. The trackball is read by the ST the same way as it reads a 
joystick (8 directions), but a trackball makes it much easier to position the 
cursor on the screen, for example. 


Mouse 

The mouse connected to the ST is basically a trackball turned upside down, 
contained in a small plastic housing about the size of a bar of soap. The 
mouse ball is moved by sliding the mouse housing on a hard surface. 

The mouse, like the trackball, has at least one control button which calls 
functions like the joystick fire button. If the mouse is connected to joystick 
port 0, the two buttons on its upper side can be read for different functions. 


Lightpen 

The lightpen is a graphics tool that plugs into the joystick port. But 
lightpens do not use an intermediate connection to the screen (like the touch 
tablet). You draw directly onto the ST monitor's screen. A photoelectric cell 
is located in the lightpen's tip. When the pen tip is held against the monitor 
screen, you can draw on the screen just as you would draw on paper with a 
regular pen. 

While the lightpen works very well on a computer monitor like the SM 124 
or (color) SC 1224, the situation is very different when you're working on 
a regular television. The thick glass of a television screen refracts light, and 
the lightpen may not be as accurate as it could be. The results of lightpen 
input are also better with a color monitor than with monochrome. 


There are many uses for the joystick ports, if you apply some thought to 
their use. But input devices cannot merely be plugged in—they require a 
control program of some sort. Games usually have built-in routines for 
joysticks or trackballs. Drawing programs accommodate lightpens and 
touch tablets. A mouse is normally used in operating systems and 
productivity programs (such as word processing). None of these devices 
will function without a control routine. 


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5.2.1.2 Disk drive 


connection 





As you know, you connect a disk drive to your ST that uses 3 1/2" 
diskettes, and can then connect a second disk drive to the first drive (see 
Chapter 1 for complete connection instructions). The disk drives for the ST 
have storage capacities of 400K and 800K. 

In addition, several third-party manufacturers make 5 1/2” IBM-compatible 
disk drives that can be connected to the ST. With one of these disk drives 
connected it is very easy to exchange data files (not programs) between the 
IBM PC and your ST. 


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5.2.1.3 Printer interface and operation 




A Centronics parallel interface port is built into the Atari ST for printer 
interfacing and connection. Centronics is the name of the firm that 
developed this interface. 

You may be wondering why the Centronics is a parallel port. Think back to 
the section on bits and bytes. You'll remember that one byte is made of up 8 
bits. The ST always sends 8 bits at a time through the Centronics 
interface—that is, 8 electrical impulses to the printer, whether these 
impulses signal off or on. The process of sending 8 bits at a time is called 
parallel transmission. 

We just read that all numbers in the decimal system can also exist in binary 
form. In much the same way, characters sent to the printer are represented 
by a code number, which is then transmitted through the parallel interface to 
the printer as a binary number. 

Another method of data transmission is serial transmission, or sending data 
one bit at a time. This method transmits data much more slowly than parallel 
transmission. Serial transmission will be explained further in section 
5.2.1.7, which deals with the RS-232 port. 

Therefore, your Centronics parallel interface makes very fast data transfer 
between your ST and a printer possible. Most microcomputers have a 
Centronics interface, because it is the standard for parallel ports. 


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The Centronics printer interface allows the printer to understand the 
character set of the ST. The symbols appearing on the printer are 
represented in number codes. For example, the number 65 represents the 
letter A, the number 32 stands for a blank space, etc. 

Several years ago an agreement was reached regarding a standard character 
set for printers. The result was called ASCII (American Standard Code for 
Information Interchange). However, this standard applies only to the 
characters with the number codes 0 to 127. The codes from 128 to 255 are 
left to the discretion of the different computer and printer manufacturers. 

You may be wondering which type of printer to buy for your ST. The most 
widely purchased printers right now are dot-matrix printers. They print 
every letter, symbol and number on paper with a series of pins that strike an 
inked ribbon in the sequence of signals received. 

Just like with the ST or any other computer, on/off binary encoding is the 
basis for the dot-matrix printer's operation. A dot-matrix printer does not 
feature crisp lettering like that produced on a typewriter, but usually has a 
printing speed of at least 50 characters per second. The reason they are so 
fast is that few moving parts are needed to drive the pins onto the inked 
ribbon and paper. A regular typewriter or even a daisywheel printer, which 
works under the same principle as a typewriter, cannot move at this speed, 
unless it is an extremely high-quality model. 

In addition to the dot-matrix and daisywheel printers, other types of printers 
include ink-jet printers, thermal printers and laser printers. 

In principle, an ink-jet printer works like a dot-matrix printer, except that it 
uses tiny nozzles to spray ink on paper as points. Unlike dot-matrix or 
daisywheel models, which tend to make a lot of noise when printing, ink-jet 
printers are very quiet. They are also expensive in comparison to dot-matrix 
and daisywheel machines. The main disadvantage of this printer (other than 
price) is that it produces poor carbon copies on triplicate computer 
paper—the ink droplets do not hit the paper hard enough to make an 
impression on the last carbon. 

Thermal printers are even quieter than ink-jet printers. The print head 
generates heat in the shape of the letter to be printed. This heat is pressed 
against heat-sensitive paper, leaving a mark on the paper. Depending on the 
type of paper used, a thermal printer can print text in a number of different 
colors (usually blue, black or red). 


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The disadvantage of the thermal printer is that the special paper is very 
expensive. If you print frequently, another type of printer would probably 
suit your needs better. 

Finally, there is the laser printer. Laser printers produce an entire page at a 
time, usually within a few seconds. A laser printer uses a small 
semiconductor laser, lenses and mirrors to shoot pulses of light onto a 
rotating drum, which picks up toner in the spots where the light hits, and 
prints out the text. This book was printed on a laser printer. For you as a 
beginner, these printers are much too expensive, with starting prices of 
about $2000. 

Almost any type or brand of printer can be connected to the ST because of 
its Centronics parallel port, which is an industry-standard interface. If you 
intend to purchase a printer, talk to your dealer or other ST users before you 
make a final decision. 


5.2.1.4 The hard disk connection 

In addition to the two disk drives you can hook up to your ST, you can also 
connect faster storage media like a hard disk drive and CD-ROM (Compact 
Disk-Read Only Memory). 
























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The hard disk drive works on the same principle as your floppy drive(s), 
except that a hard disk is mounted permanently inside the drive. Because the 
hard disk is airtight and permanently mounted, it can rotate at much higher 
speeds and work with much greater precision than a floppy disk drive. To 
give you an idea of the hard disk's speed: Floppy disks work with 250,000 
bits per second. However, the Atari hard disk drive works with 10,000,000 
bits per second (see Baud in Appendix C). 


Connecting a hard disk 

The hard disk drive is connected to your ST with a cable attached to the port 
next to the Centronics interface. The hard disk drive provides much more 
storage space than a floppy disk (10 megabytes and more). However, since 
the disk inside cannot be removed, you must delete data on the disk to make 
room for more when the disk has reached its capacity. Also, you cannot 
connect several hard disks in series as you could with floppy disk drives. 


5.2.1.5 Connecting CD-ROM players 



cfAf- 


CD-ROM players are very similar to the compact disk player you might 
have connected to your stereo system. The main difference between a 
normal compact disk and a CD-ROM is that the CD-ROM can contain large 
amounts of text and graphic information, while your regular compact disk 
contains only musical information. 


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CD-ROMs are being used now in virtually every type of computer 
application. The one with which you may be most familiar is Grolier's 
Encyclopedia. The entire multi-volume set is stored on a single CD-ROM, 
complete with illustrations and a fast search capability. The Library of 
Congress has been cataloguing the nation's books and periodicals on 
CD-ROMs for years. Perhaps the CD-ROM application most valuable to the 
average person is the complete list of poisons and antidotes stored on 
CD-ROM in the National Poison Control Center. Any poison and its 
antidote can be called up in seconds, at a time when lost seconds can mean a 
lost life. 

A CD-ROM player can be interfaced to your ST through the hard disk 
connection. However, at this writing CD-ROM players are priced much too 
expensively for the home computer user. 


5.2.1.6 The MIDI connections 



MIDI 


OUT 



The MIDI (Musical Instrument Digital Interface) connections allow your ST 
to communicate with one or more MIDI-equipped digital music 
synthesizers. The MIDI IN and MIDI OUT connections allow the computer 
and instrument to "converse". 


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The ST can memorize different processes entered through the synthesizer, 
such as tone quality, musical passages or sequences of musical tones. These 
processes can be selected from the ST through a menu or the synthesizer, 
depending on the software used to control the instrument and computer. For 
complete background information, see Abacus Software's ATARI ST 
Introduction to MIDI Programming by Dorfman and Young. 


5.2.1.7 The RS-232 interface 




The RS-232 port is much more useful to the average ST owner than the 
MIDI interface, which is designed exclusively for musically inclined ST 
users. 

For example, you may connect your ST through the RS-232 port to another 
computer equipped with an RS-232. You can then exchange data between 
both computers with a terminal program (communications software). 

Or you might connect a modem to the RS-232 port and communicate with 
other computers by means of a telephone and terminal software. A modem 
(mod ulator/ dem odulator! is a device that changes the electrical impulses in 
your computer to a form that can be transmitted over telephone lines, and 
convert computer signals received over the telephone into a form that can be 
understood by the terminal software. This method is used to communicate 
from terminal (computer) to terminal or terminal to bulletin board service 


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(BBS). A central computer known as a mainframe can even communicate 
with your ST and other computers all at once, from many miles away. You 
can also connect printers to your ST through the RS-232 port—but only 
printers that use a serial interface. 

How is the RS-232 port different from the Centronics port? You'll 
remember that the Centronics interface is a parallel interface, sending data 1 
byte (8 bits) at a time. The RS-232 is a serial port—that is, it transfers data 
one bit at a time in a long string, or series. Because of this, data transfer 
with the RS-232 port is considerably slower than with the Centronics 
interface. 


5.2.1.8 The monitor connection 

Your ST automatically recognizes whether it is connected to a color or a 
monochrome monitor. If it's a color monitor, you have a choice of two 
screen resolutions: medium resolution—640 by 200 pixels (picture 
elements, or individual points on the screen) and 4 colors; or low 
resolution—320 by 200 pixels and 16 colors. If you have a monochrome 
monitor connected, the only screen resolution available is high 
resolution—640 by 400 pixels, and no choice of colors (black or white). 

The 520ST also can be connected to a standard television instead of a 
monitor through a cable connected to the RF modulator jack on the rear of 
the computer. 


5.2.1.9 The power connection 

Finally, there is a plug for the power supply. Be sure that the power cord 
fits snugly into this connection—you know the problems a sudden power 
loss can give you.... 

We hope that this section gave you some insight into what the ST's 
interfaces do, and that you're able to apply some of this knowledge later on. 


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5.2.2 Software 


We’ll now turn to a discussion of software (programs) that are presently 
available for the ST, or will be available in the near future. 


5.2.2.1 Programming languages 

We have some knowledge of BASIC and LOGO from Chapters 3 and 4. 
There are other, more efficient programming languages for the ST. One fine 
example is the language known as C. C is a difficult language to master, but 
it has many advantages over BASIC, not the least of which is speed. 

If you have already mastered BASIC and now wish to learn C, there are a 
number of diskette-based versions of the language. They load into the ST 
the same way ST BASIC or ST LOGO loads. There are some exceptional 
books for learning the C language, such as ATARI ST BASIC to C , also 
available from Abacus. 

There are many programming languages available to run on the Atari ST. 
Once you've mastered BASIC and LOGO, try writing programs in machine 
language. The ST's 68000 chip is easy to program, and is a fast and 
efficient microprocessor. If you are interested in learning machine language, 
there are a number of assemblers and books on the market (including the 
AssemPro assembler package and ATARI ST Machine Language , both 
from Abacus). 


5.2.2.2 Application programs 

Several commercial programs for the ST were on the store shelves even 
before the ST's introduction in 1985. Scores of commercial software 
packages are now available for word processing, data management, 
financial records, bookkeeping, drawing and painting, etc. You’ll have to 
make the selection yourself, based on your own needs. It may be helpful to 
ask your Atari dealer for advice, or talk to other ST owners to assist you in 
your choices. Try to have the software demonstrated before you buy, so 
that you can get a clear idea of what you're getting for your money. 


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Some programs use the mouse and GEM, and some do not. For example, 
Digital Research, the developers of GEM, sell a word processor and a 
painting program (GEMwrite and GEMdraw, respectively) which take full 
advantage of GEM’s capabilities. Other software publishers offer a 
complete line of quality applications, including Abacus' PaintPro, 
TextPro, DataRetrieve and PowerLedger. Many games and 
educational programs have been written or converted for the ST computers, 
and more programs appear on the market every day. 

It doesn’t really matter whether we talk hardware or software. Owning an 
ST means that you own a computer for the future. We will close this chapter 
with a few words about the ST's past, as well as its future. 


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5.3 Epilogue: The significance of the Atari ST 


At the January 1985 Consumer Electronics Show in Las Vegas, Atari 
president Jack Tramiel said, "We will not sell a home computer. We will not 
sell a business computer. But we WILL sell a personal computer." 

What did he mean by that? There has never been a clear definition of the 
term personal computer. Is it a computer that does personal things, or is it 
personal in the sense that it is used exclusively at home? Or is it personal 
because it's small enough to carry around with you? 

Although the term "personal computer" will be a subject for debate for a 
long time to come, the slogan Tramiel used to introduce the ST—"Power 
without the price"—is clear to everyone. 

What is so new about the ST series of computers? First, you have at least 
512K of memory. Add to that the Motorola MC68000 microprocessor, an 
extremely fast processor. Instead of handling only 100,000 mathematical 
operations per second, as with some "home" computers, the ST's 68000 
microprocessor is capable of handling 1,000,000 calculations per second! 

Since every computer solves problems logically with mathematics, you may 
correctly assume that the faster a computer "thinks", the better it is. Your ST 
can look up the "Computers" entry in your Grolier's Encyclopedia 
CD-ROM in a few seconds, where it might take you a few minutes to find 
the entry in the book version of Grolier's. 

The ST system includes many devices at fairly low prices which you can 
connect to the ST, backing up the slogan "Power without the price." 

Furthermore, your ST has several standard interfaces for connection to 
other computers, almost every kind of printer and even electronic musical 
instruments. Also, the ST's graphic capabilities are remarkable: 512 colors 
and a high-resolution screen of 640X400 pixels. 

One other point in the ST's favor: Until now it was almost impossible for 
anyone to start computing from scratch without running into problems. One 
of the main reasons was that operating a computer required commands 
which seemed quite baffling to the average person ("Now, how do I start a 
program again: RUN, or EXEC, or FORMAT A>?"). 


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Jack Tramiel had the right idea: he designed an icon-based operating system 
which would appeal to the new user. Anyone who can see can also 
understand pictures—this shows real consideration for the common man! 

The concepts and technology behind the Tramiel Operating System and 
Graphics Environment Manager took years to develop. However, in 1984 
Tramiel and Atari realized that it was time to offer these technological 
wonders at a price people could afford. Developmental work for the ST 
began in 1984. In January 1985, the 520ST computer was introduced to a 
startled public at the Consumer Electronics Show in Las Vegas, and it has 
been selling well ever since. More recently Atari has introduced one-, two- 
and four-megabyte models of the ST. 


A serious disadvantage to writing computer books, and no one is more 
aware of it than authors and publishers, is the fact that by the time a book 
reaches the shelves of your bookstore or software store, chances are that 
changes have already been made to the computer or software. This means 
that some information in a new book may be outdated as soon as it's 
printed. For example, the early STs had their operating systems on diskette 
instead of in ROM: this meant that you had to load in TOS and GEM from 
diskette. As this book reached the editing stages, the ST was 
modified—suddenly everyone had TOS in ROM, and The Atari ST for 
Beginners was in need of a massive re-editing! 

Computer companies are living, growing entities. They develop new ideas 
and concepts, improvements and enhancements, and add these to their 
machines. To keep track of the latest in computers, you should purchase a 
computer magazine regularly. Although there is still a small delay between 
writing and publication, magazines are the most up-to-date publications 
available. 

The Appendices contain information any ST owner should know: Character 
set, number system conversions, etc. Appendix C contains a short glossary 
which defines the technical terms in this book. Finally, an index will help 
you find information and page references in this book. 

We wish you all the best with your ST. 


171 































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\ 


Appendices 


K _ 































































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Appendix A: The Atari ST character set 

The ST has a comprehensive character set: 



8 

i 

2 

3 

4 5 

s 

7 

8 

9 

R 

8 

c 

D 

E 

F 

81 


0 

£ 

0 

3 

8 

i 


G 


Jr 

F 

F 


>! 

P> 

il 

n 

y 

i 

< 

£ 

3 

H 

5 

8 

5 % 

1 

8 

3 

3 

c 

5 

£ 


x 

;5I 

21 


i 

ii 

u 

i 

x 

£ 

i 

( 

) 

* 

4 


- 

f 

/ 

31 

B 

i 

9 

A. 

i 

w 

4 

5 

s 

7 

8 

9 

1 

s 

1 

< 

— 

> 

7 

4! 

e 

8 

B 

0 

D 

E 

F 

0 

H 

I 

3 

5 

i* 

R 

L 

M 

M 

0 

51 

p 

0 R 

s 

I 

H 

y 

V 14 

X 

y 

i 

T 

L 

[ 

\ 

] 

A 

mm 

61 

\ 

a 

b 

L 

d 

e 

f 

3 

h 

i 

j 

k 

1 

n 

n 

0 

71 

p 

Q 

r 

s 

t 

u 

V 

N 

X 

y 

z 

i 

i > 

eV 

A 

8! 

c 

y 

y 

e 

A 

a 

■ a 

a 

a 

-D- 

a 

t 

A 

e 

e 

A. 

e 

i 

A 

1 

a 

i 

ii 

s 

91 

t 

a 

it 

A 

0 

0 

0 

A 

u 

V 

U 

y 

0 

u 

0 

f 

¥ 

B 

+ 

81 

jT 

3 

i 

6 

y 

U 

A* 

n 

1 3 

A* 

H 

a 

0 

L 

r 


4 

k 

! 


» 

R I 

^ i 

A 1 

2 k 

u 

A' 

e 

s 

.8 

m 

ff 

4b 

8 

R 

0 

s a 

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3 

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m 

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CS 

ii 

Ii 

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ai 

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T 

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1 

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3 

7 

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DS 

0 

u 

0 

2 

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1 

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11 

1 

1 

0 

n 


§ 

A 

«• 

El 

C( 

p r 

J-H 

ii 

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r 

$ 

9 

s 

5 

$ 

fh 

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n 

FI 

— 

4 

> 

< 

r< 

i 

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JB 1 

0 

• 

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if 

m 

2 

3 


87=1 

Sell 

8fl=LF 

8D= 

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175 





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Atari ST for Beginners 


There are two ways to call the special characters (the ones not shown on the 
keyboard). You can output the characters with PRINT CHR$ (), or you 
can access the characters directly from the keyboard: 


CHR$ 

(1) 

<ControlxA> 



CHR$ 

(2) 

<ControlxB> 



CHR$ 

(4) 

<ControlxD> 



CHR$ 

(5) 

<ControlxE> 



CHR$ 

(6) 

<ControlxF> 



CHR$ 

(9) 

<ControlxI> 

or 

<Tab> 

CHR$ 

(11) 

<ControlxK> 



CHR$ 

(12) 

<ControlxL> 

or 

<ControlxShiftx+> 

CHR$ 

(14) 

<ControlxN> 

or 

<Controlx,> 

CHR$ 

(15) 

<Control><0> 


CHR$ 

(16) 

<ControlxP> 

or 

<Control><0> 

CHR$ 

(17) 

<ControlxQ> 

or 

<Controlxl> 

CHR$ 

(18) 

<ControlxR> 



CHR$ 

(19) 

<ControlxS> 

or 

<Control><3> 

CHR$ 

(20) 

<ControlxT> 

or 

<Control><4> 

CHR$ 

(21) 

<ControlxU> 

or 

<Control><5> 

CHR$ 

(22) 

<ControlxV> 



CHR$ 

(23) 

<ControlxW> 

or 

<Control><7> 

CHR$ 

(24) 

<ControlxX> 

or 

<Control><8> 

CHR$ 

(25) 

<ControlxY> 

or 

<Control><9> 

CHR$ 

(27) 

<Esc> 



CHR$ 

(26) 

<ControlxShiftxless than (<)> 

CHR$ 

(26) 

<ControlxShiftxO> 

CHR$ 

(26) 

<Control><6> 



CHR$ 

(26) 

<Controlx-> 




If you want to display the Atari symbol on the screen, for example, you can 
do it from program mode in BASIC by using: 

PRINT CHR$(14); CHR$(15) 

Or you can call the symbol in direct mode by pressing the following keys: 
Press <ControlxN>, then press <Control><0> 


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Appendix B: Conversion programs 


1. Converting decimal to binary 

Problem: Convert 255 decimal to its binary equivalent 

10 INPUT "DECIMAL NUMBER";A 
20 FOR N=15 TO 0 STEP-1 

30 IF A=INT(2 A N) THEN A$=A$+"1" : A=A—INT (2 A 
40 IF A>INT(2 A N) THEN A$=A$+"1":A=A-INT(2 A 
50 IF Z=0 THEN A$=A$+"0" 

60 Z=0:NEXT N 
70 PRINT A$ 

RUN 

DECIMAL NUMBER ? 255 
RESULT: 0000000011111111 


2. Converting binary to decimal 

Problem: Convert 11111111 binary to its decimal equivalent 

10 INPUT "BINARY NUMBER";A$ 

20 FOR N=1 TO LEN(A$) 

30 IF MID$(A$,N,1)="1" THEN Z=1 
40 IF Z=1 THEN Z=0 : A=A+2 A (LEN (A$) -N) 

50 NEXT N 
60 PRINT A 

RUN 

BINARY NUMBER? 11111111 
RESULT: 255 


177 


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3. Converting decimal to hexadecimal 

Problem: Convert 255 decimal to its hexadecimal equivalent 

PRINT HEX$(255) 

RESULT: FF 

4. Converting hexadecimal to decimal 

Problem: Convert $FF hexadecimal to its decimal equivalent 

PRINT &HFF 
RESULT: 255 

5. Converting decimal to octal 

Problem: Convert 255 decimal to its octal equivalent 

PRINT OCT$(255) 

RESULT: 377 

6. Converting octal to decimal 

Problem: Convert 377 octal to its decimal equivalent 

PRINT &0377 
RESULT: 25 

7. Converting binary to hexadecimal 

Problem: Convert 11111111 binary to its hexadecimal equivalent 

10 INPUT "BINARY NUMBER";A$ 

20 FOR N=1 TO LEN(A$) 

30 IF MID$(A$,N,1)="1" THEN Z=1 


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40 IF Z=1 THEN Z=0:A=A+2 A (LEN(A$)-N) 
50 NEXT N 
60 A%=A 

70 PRINT HEX$(A%) 

RUN 

BINARY NUMBER? 11111111 
RESULT: FF 


8. Converting hexadecimal to binary 

Problem: Convert $FF hexadecimal to its binary equivalent 

10 INPUT "HEXADECIMAL NUMBER";A$ 

20 A$="&H"+A$ 

30 A=VAL(A$):A$="" 

40 FOR N=15 TO 0 STEP-1 

50 IF A=INT(2 A N) THEN A$=A$+"1":A=A-INT(2 A 
60 IF A>INT(2 A N) THEN A$=A$+"1":A=A—INT(2 A 
70 IF Z=0 THEN A$=A$+"0" 

80 Z=0:NEXT N 
90 PRINT A$ 

RUN 

HEXADECIMAL NUMBER ? FF 
RESULT: 0000000011111111 


179 


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Atari ST for Beginners 


Appendix C: Mini glossary for computer users 


Assembler: 

Program used to access and program a computer in its native 
language (see Machine language) 


BASIC: 


High-level programming language that can be learned with 
relative ease, since commands are easily edited and errors can 
be found immediately. Considered to be one of the most 
popular programming languages ever written 


Baud: 

Speed of transfer from computer to peripherals, measured in 
bits per second; standard rates are 300, 1200,4800 and 9600 
baud 

Binary system: 

Number system using only 0's and l's; computers use the 
binary system for all internal computations 

Bit: 

The smallest information unit in a computer (8 bits=l byte=l 
character) 

Bug: 

Program or hardware error; based on retired US Navy 
Admiral Grace Hopper's tale of an actual insect "crashing" a 
relay-driven computer in the 1940s 

Byte: 


Equal to 8 bits; 1 byte can be a letter or character. You gauge 
computer memory in 1 Kilobyte (1024 byte) increments 


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C: 


High-speed programming language. Since error detection 
does not take place until compiling (conversion into machine 
language), the language is very difficult to learn (see also 
BASIC) 

Centronics: 

Company that developed the standard printer connection on 
your ST. This interface will connect directly to most printers 
(see Compatibility) 


Chip: 


One small electronic component containing a number of 
miniaturized components and circuits, created by a 
photographic process; also called integrated circuit 

Compatibility: 

Easy exchange of hardware and software between different 
types of computers 

Control code: 

Function performed by a control key, either in direct mode or 
in a program 


CP/M: 

Abbreviation for Control Program for Microprocessors; 
operating system used mainly for commercial software 
programs 

CPU: 


Central Processing Unit. The heart of the computer that 
controls all data flow; can be a single integrated circuit or a 
series of chips 


182 



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Cursor: 

Character on screen that shows where your text will appear 

Database: 

Software used for filing, mailing lists, recipes—anything that 
requires keeping track of files 

Debugging: 

Elimination of program errors (see Bug) 

Decimal system: 

Number system using the numerals 0 to 9 

Diskette: 


Mylar disk coated with a magnetic substance and enclosed in 
plastic case; used for data storage. Standard diskette sizes are 
3", 3.5" and 5.25" (older diskettes came in 8" size) 

Disk drive: 

Device for loading and saving files on diskettes 

Dot-matrix printer: 

High-speed printer with a head consisting of a matrix of pins 
that print letters, characters and graphics on paper as a series 
of dots 

Drop-down menu: 

Menu that drops down when the mouse pointer is placed on a 
selection of the menu bar 


Editing: 


Correcting program errors, or typing in new program lines 
on the computer 


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EPROM: 


Chip that retains data "burned" into it, but data can be erased 
by ultraviolet light for later re-burning 

Error message: 

Message displayed on the screen in response to any error; 
messages can be in text or numerical form 

Fire button: 

Button found on joysticks, paddles, etc.; used mostly in 
game control 

Floppy diskette: 

Flexible magnetic disk that stores data (see Diskette) 
Function keys: 

Ten keys arranged across the top of the ST keyboard as 
<F1>, <F2>, etc. Functions can be assigned by the user or 
by programs 


GEM: 


Graphics Environment Manager; graphic operating system of 
the ST which allows up to four windows onscreen at a time 
and sets up the mouse as an input device 


Graphic: 


Any diagram, drawing or artwork produced by a computer, 
or created by a human being using a computer as an artistic 
medium 

Hard disk: 

Device used for rapid storage and loading of programs. 
Unlike floppy disks, the hard disk is a self-contained, sealed 
unit that can store much more data and access data much 
faster than a floppy drive 


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Hardware: 

All mechanical and electronic parts of the computer: disk 
drive, computer, etc. (see Software) 

Hexadecimal system: 

Number system consisting of 16 numerals/letters (0 to 9 and 
A to F); closely matches binary system in structure, and is 
used in machine language programming 


Icon: 

Small picture representing an object or action (e.g., ST 
program icons are drawn as blocks; disk drive icons look like 
file cabinets) 

Input device: 

Peripheral used to convey information from you to the 
computer; for example, keyboard, joysticks and mouse 

Integrated circuit 

(see Chip) 

Interface: 

Connection between computer and other devices 
(peripherals); the ST has a Centronics parallel interface for 
printer connection, and an RS-232 port for modem or serial 
printers 

Interpreter: 

"Go-between" for computer and programming languages; 
translates the programming language into machine language, 
which the computer understands. BASIC and LOGO are 
interpreted languages 


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Atari ST for Beginners 


Joystick: 


Control device with movable stick and fire button, used 
mostly for games 


Kilobit: 


1024 bits=128 bytes; computer memory measurement 


Kilobyte: 

1024 bytes; computer memory measurement 

Lightpen: 

Pen-shaped device with a photocell at its tip; allows direct 
drawing on the monitor screen with the help of software 
designed for the purpose 


LOGO: 


Easy-to-leam interpreted programming language; uses 
graphically-oriented "turtle" and English-like commands 

Machine language: 

Programming language understood by the computer; 
commands in BASIC or LOGO are turned by the interpreter 
into machine language; machine language programs are much 
faster than LOGO or BASIC programs as there is no 
interpreter involved 

MC68000: 

Motorola's 16-bit microprocessor used as a CPU in the ST 
Megabyte: 

1024 kilobytes, or 1,048576 bytes; computer memory 
measurement unit 


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Memory: 


Electronic "space" available in a computer for data storage; 
also, different types of memory storage: RAM, ROM, 
EPROM, PROM 

Microprocessor 

(see CPU) 


MIDI: 

Musical Instrument Digital Interface; connection in the ST 
that interfaces to one or more MIDI-equipped music 
synthesizers or samplers (see Synthesizer and Sound) 

Modem: 


Short for mo dulator/ demo dulator: allows transfer of data 
over telephone lines; can be a direct connection between 
computer and telephone jack or an acoustic modem, which 
sends and receives data acoustically over the telephone 

Modulator: 

A chip that creates a computer output so it can be viewed on a 
monitor or television 


Monitor: 


Special video screen for displaying data; offers higher 
resolution than a normal television set 


Mouse: 


Input device consisting of a small box with one or two 
buttons on top, and a small ball poking out the bottom; the 
onscreen cursor can be moved by placing the mouse on a 
table and moving it about 


187 




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Octal system: 

Number system made up of eight numerals (0 to 7); counted 
as 01234567 10 11 12 etc.; similar to binary and 
hexadecimal systems 

Operating system: 

Program or internal coding that regulates control between 
computer and peripherals; CP/M and GEM are operating 
systems 

Output device: 

Peripheral used for conveying information from the 
computer; for example, a monitor, television set or printer 


Paddles: 


Input device with potentiometer and fire button, used mostly 
for game control; unlike joysticks, paddles operate in only 
two directions 

Parallel data transfer: 

Binary data is transferred over a cable or interface eight bits 
at a time (see also Serial data transfer) 

Peripheral: 

All hardware connected to a computer, such as printers, disk 
drives, etc. 


Printer: 


Output device that prints computer data on paper (called a 
printout or hardcopy); various methods are used to print the 
data, e.g., dot-matrix, daisywheel, ink-jet, thermal and laser 
printing 


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Programming language: 

Series of commands and instructions that allows the 
programmer to control the computer; examples include 
machine language, and higher-level languages such as 
BASIC, LOGO and C 


PROM: 


Programmable Read Only Memory; chip onto which data can 
be recorded, or "burned; unlike EPROMs, PROMs cannot be 
erased 


RAM: 

Random Access Memory; memory with directly alterable 
contents; contents remain in memory until electric power is 
turned off 

Relay: 

Electromechanical switch used to make early computer logic 
circuits; relays were later replaced by vacuum tubes, 
transistors and chips 

RGB: 

Abbreviation for Red-Green-Blue; refers to high-quality 
color monitors, or the interface to connect such a monitor to a 
computer 

ROM: 


Read Only Memory; ROMs do not lose their data in their 
memory, even when the computer power is turned off (see 
also EPROM, PROM and RAM) 

RS-232 port: 

Interface used with modems or printers; uses serial data 
transfer (see next entry) 


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Serial data transfer: 

Data transfer occurring one bit at a time, i.e. in serial (see 

Parallel data transfer) 

Software: 

Anything used by the physical components of a computer to 
accomplish its processing (see Peripherals, Hardware); 
programming languages, operating systems and programs 
are all software 


Sound: 


In this context, waveforms created by a chip within an 
electronic device and converted to acoustical vibrations by a 
loudspeaker; the ST has a Yamaha YM-2149 sound chip built 
in. Also, the ST can control MIDI-equipped digital music 
synthesizers through its MIDI ports 

Spreadsheet: 

Program that displays a series of rows and columns and 
allows you to perform calculations, budgeting, "what if.." 
simulations 


String: 


Series of alphanumeric characters, placed in quotes (e.g., 
"This is a string"); a variable made of a string, 
designated by a dollar sign after the variable name (e.g., 
A$="This is a string variable") 

Synthesizer: 

Electronic musical instrument capable of reproducing tones 
and sounds through a series of tone generators, filters and 
controls (see MIDI) 


TOS: 


Short for Tramiel Operating System, named after Atari's Jack 
Tramiel; TOS is your ST's operating system 


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Touch tablet: 

Input device used for graphics; a plastic stylus or your finger 
draw on the surface of a touch-sensitive "pad" 

Transistor: 

Electronic component developed in the late 1940s; a des¬ 
cendant of relays and vacuum tubes, later replaced by chips 

User-friendly: 

Refers to computers or operating systems designed for ease 
of use by the new computer owner; TOS is a user-friendly 
operating system 


Variable: 


Data stored in a certain area of memory; a quantity which can 
contain a number of values 


Window: 


Adjustable subscreen on the ST, used in editing, reading disk 
directories, input, etc.; the ST can display up to four 
windows on the screen at a time 

Word processor: 

Software program that converts your ST into a writing tool; 
ease in editing, rewriting, text deletion and draft work make 
the word processor a great improvement over a typewriter 


191 




























Abacus 


Atari ST for Beginners 


Appendix D: ST BASIC error messages 


Here is a collection of the most important error messages encountered 

in ST BASIC, including explanations of each message: 

1: Undefined error. The error is not understood by the ST. If the 

error doesn't match any other error known to the operating 
system, an error 1 will occur. 

2: Something is wrong. This error message results mostly from a 

misspelled BASIC command, e.g., GTO instead of GOTO; 
correct the spelling to fix the error. 

3: RETURN statement needs matching GOSUB. The RETURN must 

be preceded by a GOSUB. You must jump to a subroutine with 
GOSUB before going back to the main program with RETURN. 

6: Number too large. The number input was less than IE-19 

(-10,000,000,000,000,000,000, or -10 quintillion) or more 
than 1E+18 (1,000,000,000,000,000,000, or 1 quintillion). 

7: Not enough memory. There may not be enough memory 
available to run a program, even if you own a 1040ST. The 
reason for this error can be either too long a program, or too 
many variables in a program. 

11: You cannot divide by zero... Just as in mathematics, the ST 
cannot do the impossible. 

13: Types of values do not match. You cannot assign a string to a 
numerical variable. For example, A cannot equal "A". For this 
you must use a string variable, like A$. 

15: Strings cannot be more than 255 characters long. If you wish to 
store a longer text in strings, you'll have to use multiple string 
variables. 

17: CONT works only in BREAK mode. The CONT(inue) command 
works only if the program was stopped by a BREAK or by 
pressing <ControlxG>, or if END appears in the program. 


193 



Abacus 


Atari ST for Beginners 


23: Program line too long. A single program line can have a 
maximum of 255 characters. 

30: Window number invalid. You may only use numbers 0 to 3 
with window commands (0=EDIT, 1=LIST, 2=OUTPUT, 
3=COMMAND); any other values cause this error. 

53: File not found on disk drive specified. The program name 
cannot be found on the disk. Look at the disk directory before 
loading a program with Load "Name". 

58: File exists. A file already stored on diskette has the same name 
as you had typed in under Save. You'll have to delete the old 
file from the diskette, use another diskette, or change the name 
of the file you wish to save. 

61: Disk full. You'll have to either delete programs from this disk to 
free up some memory, or use another disk that has free space. 

64: Invalid file name. A filename may consist of up to eight 
characters plus a three-character file extension. 

99:- BREAK -This appeal's on the screen if you have stopped 

a running program with <ControlxG>. You may continue the 
program run by typing in CONT. 

103: Invalid line number. Line numbers may not be less than 0 or 
greater than 65529. 

106: Line number does not exist. With GOSUB or GOTO, you may 
not jump to a line number that does not exist. 

107: Number too large for an integer. Integer values can be no less 
than -32767 and no greater than +32767. 

108: Input data is not valid, restart input from first item. If a 
numerical variable is expected in response to an INPUT 
command, you may not enter a string variable. You have to 
restart INPUT from the first item to be input. 

109: STOP. Program halt. The program may only be restarted with 
RUN. 


194 



Abacus 


Atari ST for Beginners 


204: FOR statement needs a NEXT or WHILE needs a WEND. A 
FOR. . . NEXT loop must consist of a FOR and a NEXT, or the 
program loop cannot be carried out successfully. A 
WHILE . . .WEND loop needs both a WHILE and a wend for 
successful execution. 

205: NEXT statement needs a FOR or WEND needs a WHILE. Program 
loops need both elements of each loop (see 205). 

221: System err or...please restart. There is only one thing you can do 
about this error—restart the system by pressing reset, or turn the 
computer off, then on again. 

223: Too many FOR loops. You are not allowed to nest too many 
FOR. . . NEXT loops within one another. 



195 


































































Index 


<Altemate> key 

<Altemate><Help> — see Hardcopy 

53 

Arithmetic Logic Unit (ALU) 

155 

ASCII 

162 

AUTO (BASIC) 

92 

BACK (LOGO) 

126-128,139 

<Backspace> key 

54 

BASIC 

61-115,181 

debugging 

92-95 

disk commands 

96-98 

error messages 

193-195 

graphic commands 

87-91 

programs 

99-114 

vocabulary 

66-98 

Binary system 

148-151,181 

Bit 

152,181 

BOX (LOGO) 

134 

Bug 

144,181 

Byte 

152,181 

C (language) 

168,182 

<Caps Lock> key 

53 

CD-ROM 

164-165 

Central processing unit (CPU) 

154-155,182 

Centronics parallel interface 

161-163,183 

Chessboard problem program 

106-108 

Chips 

144-147,182 

CHR$ () (BASIC) 

176 

CIRCLE (BASIC) 

87 

CIRCLE (LOGO) 

135 

CLEARW (BASIC) 

65,74,115 

Close 

34 

Close box 

16,22 

CLOSEW (BASIC) 

89 

Close Window 

34 

<Clr/Home> key 

56 

COMMAND window (BASIC) 

62,64 

CONT (BASIC) 

93,115 


197 


<Control> key 

53,176 

Control Panel 

28-29 

Conversion programs 

112-114,177-179 

Copying 

diskettes 

43 

files 

44-45 

CPU — see Central Processing Unit 

CS (LOGO) 

125,131,139 

CT (LOGO) 

125,139 

Cursor keys 

56 

Data files 

44,50-51 

Data transfer 

161-163,166-167,188,190 

Debugging 

144,183 

BASIC 

92-95 

LOGO 

140 

Decimal system 

148-149 

DELETE (BASIC) 

92 

<Delete> key 

54 

Deleting files 

44-45 

Desk menu 

23-29 

Desktop — see GEM Desktop 

Dialog box 

24 

Digital Research (DR) 

121,169 

DIM (BASIC array dimensioning) 

85-86,115 

Diskette 

183 

Disk directory 

14-16 

Disk drive 

5,40,96-98,160,183 

Double-click 

14, 183 

Drop-down menus 

15,23,183 

EDIT window (BASIC) 

62-63,94-95 

Editing keys 

56 

ELLIPSE (BASIC) 

88 

ELLIPSE (LOGO) 

135-136 

END (LOGO) 

130-131,139 

<Enter> key 

54,55,57 

EPROM 

145-146,184 

<Esc> key 

54 

File extensions 

39-40,49-50 

File menu 

30-37 


198 


FILLATTR (LOGO) 

FOLLOW (BASIC) 

FOR...NEXT (BASIC) 

Format... 

Formatting diskettes 
FORWARD (LOGO) 

Full box 

FULLW (BASIC) 

Function keys 

GEM 

GEM Desktop 
Ghost icon 

GOSUB...RETURN (BASIC) 

GOTO (BASIC) 

GOTOXY (BASIC) 

GRAPHICS DISPLAY window 

Hardcopy 
Hard disk 
Hardware 
<Help> key 
Hexadecimal system 
HIDETURTLE (LOGO) 

Icons 

IF...THEN...ELSE (BASIC) 

Ink-jet printer 
INPUT (BASIC) 

<Insert> key 

Install Application... 
Install Disk Drive... 
Install Printer... 

Joystick 
Joystick ports 

Kilobit 

Kilobyte 

LEFT (LOGO) 

Lightpen 


137 

93 

71-72,115 

35-37 

35-37 

126-128,139 

18 

89 

56,184 

12.24.184 
12 
13 

72,115 

68- 69,115 

89 

(LOGO) 121 

42,57 

163-164,184 

185 

57 

151.185 
136 

12.49.185 

69- 70,115 

162 

67-68,115 

56 

39-40 

39 

27 

157.186 
6,157-159 

152.186 
152-153,186 

126-128,139 

159.186 


199 


LINEF (BASIC) 

LIST (BASIC) 

LIST window (BASIC) 

LOGO 

debugging 

vocabulary 

LOGO DIALOGUE window 
Lotto numbers program 

MAKE (LOGO) 

Machine language 

Memory 145 

Menu bar 

Microprocessor 

MIDI —see Musical Instrument Digital Interface 

Modem 

Monitor 

Mouse 

MOUSE (LOGO) 

Move bar 

Musical Instrument Digital Interface (MIDI) 

NEW (BASIC) 

New Folder 
NODES (LOGO) 

Octal system 
Open 

OPENW (BASIC) 

Operating system 
Options menu 
OUTPUT window (BASIC) 

Paddle 

Parallel data transmission 

Parallel interface —see Centronics parallel interface 

Pause (LOGO) 

PCIRCLE (BASIC) 

PELLIPSE (BASIC) 

PENDOWN (LOGO) 

PENUP (LOGO) 

PRINT (BASIC) 


90 

92.115 
62 

119-140,186 

140 

122-139 

121 

109-112 

123-125,139 

168,186 

147,152-153,187 

12 

154-155,187 

166.187 

4.167.187 

6.159.187 
138 

16 

165-166,187 

74.115 
33-34 

138 

151.188 
30-31 

88 

11,188 

38-42 

62,65 

158.188 
161-162,188 

140 

91 
91 

132-133,139 

132-133,139 

66.115 


200 


PRINT (LOGO) 

Printers 

Print Screen 
Programming languages 
PROM 

Quit (BASIC) 

RAM 

Red-Green-Blue (RGB) 

Relays 

REM statements (BASIC) 

RENUM (BASIC) 

REPEAT (LOGO) 

<Retum> key 
RIGHT (LOGO) 

RND (BASIC) 

ROM 

RS-232 interface 
RUN (BASIC) 

Save Desktop 
Scrolling 

Serial data transmission 

Serial interface —see RS-232 interface 

Set RS232 Config. 

SETFILL (LOGO) 

Set Preferences... 

<Shift> key 

Show as icons/Show as text 
Show Info 
SHOWTURTLE (LOGO) 

SHUFFLE (LOGO) 

Size box 
Software 
Sort... 

SORT (LOGO) 

STOP (BASIC) 

Synthesizer 


122-123,139 

27,42,161-163,188 

42 

52,155,168,189 

147,189 

98 

147.189 
28,29,189 

143-144,189 

73.115 
92 

128-130,139 

54 

126-128,139 

105,115 

145-146,189 

166-167,189 

66.115 

42 

20-21 

161,167,190 

25-26 

137 
41 

53,56 

37 

31-33 

136 

138 
16,19 

168.190 
37 

138 

115 

165-166,190 


201 


<Tab> key 

53 

Telephone book program 

99-101 

Terminal 

166 

Thermal printer 

162-163 

TO (LOGO) 

130-131,139 

TOS 

23,39-40,146,171,190 

Touch tablet 

158,191 

TRACE (BASIC) 

93 

TRACE (LOGO) 

140 

Trackball 

158 

Tramiel, Jack 

Tramiel Operating System—see TOS 

170-171, 190 

Transistor 

144,191 

Trash icon 

12-13 

TROFF (BASIC) 

93 

TRON (BASIC) 

93 

TURTLEFACTS (LOGO) 

138 

<Undo> key 

57 

UNTRACE (BASIC) 

93 

User-friendly 

14,191 

Variables 

75-86,191 

decimal 

77-81 

integer 

77-81 

string 

81-84,190 

View menu 

37 

Vocabulary program 

102-105 

VT52 Emulator 

25 

Watch (LOGO) 

140 

Windows 

15,191 

BASIC 

62-63 

closing 

22 

enlarging and reducing 

18-20 

moving 

17 

opening 

14-16 

Write-protect 

33-34 

Z80A microprocessor 

154 

Zuse, Konrad 

143 


202 



Catalog of Al 

for the 

oac 

m 

US 

SHIBSII] 

mm 

Products 

^u 1 

Abacus, P.O. Box 7219, Grand Rapids, Ml 49510 


















Selected Books from our^^fj^g^ Reference 


Library 


GEM Programmer's Reference 

Atari ST GEM Programmer's Reference is an indispensable guide if you’re a 
serious ST programmer needing detailed information on GEM. Atari ST 
GEM Programmer’s Reference is written especially for the ST and has an 
easy-to-follow format. The GEM routines are explained with examples 
written in both C and 68000 assembly language. 

Topics include: 

• Overview of GEM: VDI, AES, 

GDOS, GIOS 

• Intro to programming with GEM 

• The ST Development System 

• Using the Editor, C-compiler, 

Assembler and Linker 

• Inside GEM: programming the Virtual 
Device Interface (VDI) 

• Inside GEM: programming the 
Application Environment Services (AES) 

GEM Programmers Reference is a complete programming handbook for all 
ST users. 412 pages. Optional diskette available. 


f m 



Abacus 


Software 


GEM Programmer’s Reference 
Optional Diskette 


Suggested Retail Price: $19.95 
Suggested Retail Price: $14.95 


"Anyone interested in learning how 
to manipulate the VDI or the AES 
will want to have this book at their 
fingertips ..." 

—Richard Kaller 
ST Applications 

"Despite its title, the Atari ST GEM 
Programmer's Reference is really a 
complete programming handbook 
for the ST." 

—Donald Evan Crabb 
Byte 


Optional Program Diskettes 

Don't foiget optional program diskettes are available for all the books 
in the Atari ST Reference Library (except where noted). These optional 
diskettes contain all the program listings printed in the books, and will 
save you hours of tedious typing. 


Each optional diskette: 


$14.95 



Auri ST, 520ST, 1040ST, TOS, ST BASIC and ST LOOO are trademarks or registered trademarks of Atari Corp. OEM is a registered trademark of Digital Research Inc. 



























































Selected Books from our 



Reference 

Library 


Machine Language 

Atari ST Machine Language is the complete introduction to the high-speed 
world of 68000 machine language on the Atari ST. Atari ST Machine 
Language is required reading if you're interested in getting out the full 
potential built into the spectacular MC68000 microprocessor used in the 
Atari ST line of computers. Topics include: 

• Logical operations and bit manipulations 

• 68000 register structure and data organization 

• Fundamentals of assembly language programming 

• Operating system and programs 

• Solutions to typical problems 

• Program development 

• Step by step programming 

• Program and memory structure 





Atari ST Machine Language also contains many simple programs that 
progressively teach the fundamentals of programming in 68000 machine 
language. 280 pages. Optional diskette available. 



Atari ST Machine Language Suggested Retail Price: $19.95 

Optional Diskette Suggested Retail Price: $14.95 


Tricks & Tips 

Atari ST Tricks & Tips is a fantastic collection of ST programming tools 
and techniques that every ST user will find valuable. Teaches you how to 
define BASIC, assembler and C programs with the advanced programming 
techniques found exclusively in Atari ST Tricks & Tips. Topics include: 

• Special ST BASIC commands 

• "Safe" locations for M/L programs 

• Using the VDISYS commands 

• Mastering powerful GEM applications 

• Producing fantastic graphics 

• Building a RSC file 

Program listings included in Atari ST Tricks & Tips: 

• Super-fast RAM disk 

• Time-saving printspooler 

• Color print hardcopy 

• Plotter output hardcopy 

• Auto-starting TOS application 

• Creating accessories 



It 

T 

fMDfkS? 

'RICKS & TIPS III 

Valuable collection of soHytoty tpols 
and programming hints 





AD« 

Abacui 

lumnn 

s [Mm Software 


Plus much more—and all programs are included in the price of the book! 
Full four-color plates in appendix show you the STs graphic capabilities. 
Fully indexed. 260 pages. 

Atari ST Tricks & Tips Suggested Retail Price: $19.95 

Optional Diskette Suggested Retail Price: $14.95 


".. .this book a best-seller and I can 
understand why” 

—Pamela Rice Frank 
Current Notes 



Anri ST, 520ST, 1040ST, TOS, ST BASIC and ST LOGO are trademarks or registered trademarks of Atari Corp. GEM is a registered trademark of Digital Research Inc. 



























































Graphics & Sound 


Atari ST Graphics & Sound teaches the ST user how to create graphics and 
make full use of the built-in sound capabilities of the Atari ST. Example 
programs listed in Atari ST Graphics & Sound are written in BASIC, C, 
LOGO and Modula-2. Topics include: 


Mirror and rotation 
Graphics under GEM 
Coordinate transformations 
Raster and vector graphics 
Principles of music synthesis 
Sound chip 

Plotting math functions in 2D & 3D 


Moire patterns 
Bar and pie charts 
Fractals 

Waveform generation 

The ST as a synthesizer 

MIDI control of musical devices 


Atari ST Graphics & Sound is a must for the ST owner who wants an in- 
depth look at creating sophisicated graphics and surprising music and sound 
with the ST. 255 pages. Optional diskette contains dozens of graphics and 
sound programs. 


Atari ST Graphics & Sound 
Optional Diskette 


Suggested Retail Price: $19.95 
Suggested Retail Price: $14.95 


LOGO User's Guide 

ST LOGO was designed specifically to take full advantage of the Atari STs 
fantastic graphic capabilities. LOGO'S English-like words may be extra¬ 
ordinarily easy to learn, yet LOGO programs are actually built along the 
lines of advanced artificial intelligence languages like LISP. Atari ST 
LOGO User's Guide gently introduces the reader to the fundamentals of ST 
LOGO with numerous examples, dozens of actual screen illustrations and 
exercises that optimize the STs features. Then it moves on to work with 
the more advanced features LOGO has to offer—readers will soon be 
programming highly complex tasks on their STs under LOGO. Topics 
covered: 

• Thorough introduction to GEM, windows, and the mouse 

• Randomizing and repetition 

• Programming with recursion 

• LOGO words & lists 

• Data structures in LOGO 

• Error output 

• Computing with LOGO 

• ST LOGO system, input and output commands 

• Programs as lists 

Atari ST LOGO User’s Guide covers everything your customers need to 
know about this acclaimed teaching and graphics language. 370 pages. 


Atari ST LOGO User’s Guide 
Optional Diskette 


Suggested Retail Price: $19.95 
Suggested Retail Price: $14.95 


filCSJ SOUND 



Software 



" A worthwhile addition to your 
reference library... contains many 
examples & demonstration programs 
in the LOGO language." 

—Bruce Laubenheimer 
Computer Shopper 

"For those folks who have been 
waiting for an excuse to start play¬ 
ing with LOGO, this may be it!" 

—Steve Tearle 
Atari Journal 


Atari ST, 520ST, 1040ST, TOS, ST BASIC and ST LOGO are trademarks or registered trademarks of Atari Corp. GEM is a registered trademark of Digital Research Inc. 


















































Selected Books from our JkSlF utaanr* 8 


Peeks & Pokes 

PEEK and POKE commands act as bridges between the user and the Atari 
STs operating system through ST BASIC. Atari ST Peeks & Pokes 
enhances the user’s knowledge of the ST and programs with numerous 
PEEK and POKE examples. 

Atari ST Peeks & Pokes clearly explains a number of the most important 
PEEKS and POKES and their application to common programming 
problems. At the same time, this book gives you an excellent look at the 
architecture and operation of the exciting Atari ST. Topics include: 

The STs configuration and interfaces 
The "intelligent" keyboard 
The mouse as a paintbrush 
Pointer and stack 
Customizing the desktop 
Important PEEKs & POKEs 
Making your own fill patterns 
ST communications 
Direct disk access 
Internal memory configuration 

Atari ST Peeks & Pokes unlocks the secrets hidden within the ST with an 
excellent collection of "quick hitters" and information. 200 pages. 


Atari ST Peeks & Pokes 
Optional Diskette 


Suggested Retail Price: $16.95 
Suggested Retail Price: $14.95 


BASIC Training Guide 

Atari ST BASIC Training Guide for the Atari ST is a functional, 
educational and well-written introduction to ST BASIC. Quickly teaches 
you the fundamentals of programming with an introduction to program 
analysis, problem analysis, algorithms, and BASIC commands. This 
systematic book makes learning programming in the popular BASIC 
language quicker and easier than ever before. 

Quizzes throughout the book help you learn to "think in BASIC" while 
you'r getting a practical grounding in the language. Topics include: 

• Data flow and program flowcharts 

• Advanced programming techniques 

• Menus 

• Multi-dimensional arrays 

• Sort routines 

• File management 

• BASIC under GEM 

In addition, Atari ST BASIC Training Guide also contains advanced 
programming techniques if you already know ST BASIC. 312 pages. 


BASIC Training Guide 
Optional Diskette 


Suggested Retail Price: $16.95 
Suggested Retail Price: $14.95 


m 

Peeks & Pokes 

The authoritative insider's guide 



Abacus iniiiii;it Software 


MRIASu 3 

BASIC Training Guide 



'The Atari ST BASIC Training 
Guide is a first-class text for ST 
BASIC users. It is clear , thorough, 
well-written and remarkably free of 
errors and typos... does a good jog 
of introducing the user to ST 
BASIC programming fundamentals. 
It also provides a valuable reference 
section for the more advanced user." 

—David Plotkin 
Antic 


Anri ST, 520ST, 1040ST, TOS, ST BASIC and ST LOOO are trademarks or registered trademarks of Atari Corp. OEM is a registered trademark of Digital Research Inc. 

















































































Selected Books from L? b f ® a r ® nce 


Introduction to MIDI Programming 

The digital music synthesizer is the musical instrument of the 80s. You 
can now buy synthesizers for under $1000 (as low as $250), play at least 
four voices at a time, and they can be connected to home computers through 
the Musical Instrument Digital Interface (MIDI) for computer control. The 
Atari ST is ideal for MIDI interfacing, since it has a built-in MIDI port. 
This means it's ready to hook up to any digital electronic musical 
instrument equipped with MIDI ports. 

ST Introduction to MIDI Programming gives you the groundwork for 
discovering the infinite musical possibilities of the Atari STs MIDI 
interface and your synthesizer. Topics include: 

• Introduction to MIDI programming 

• MIDI STANDARD and MIDI LANGUAGE 

• Programming your synthesizer 

• How to buy MIDI software 

• Using the extended BIOS 

• Source code from Xlent Software’s ST 
MUSIC BOX® AUTO-PLAYER program 

• C source codes for many programs and functions 



Essential reading for anyone who uses the STs MIDI port 256 pages. 

Introduction to MIDI programming Suggested Retail Price: $19.95 
Optional Diskette Suggested Retail Price: $14.95 

BASIC to C 

Atari ST BASIC to C was written expressly for those of you who've 
learned the essentials of ST BASIC, but are hesitant to try another 
language. This excellent book quickly takes you beyond the BASICS and 
teaches how to program in the C language—-the language of choice for 
thousands of advanced program developers. Atari ST BASIC to C places 
simple BASIC programs and their equivalents in C code side-by-side, with 
clearly-written comparisons between the two languages. Now you can learn 
the groundwork for C programming in only one day ! Topics covered: 

• Development, applications and the benefits of C 

• Functions and text output 

• Program format 

• Loops and comments 

• Data input 

• Arithmetic in C 

• Control structures 

• Data types in C 

• C pointers and arrays 

• Common errors made by BASIC programmers 

Atari ST BASIC to C skillfully guides the BASIC programmer through the 
necessary steps for programming in the C language. An essential addition to 
the libraries of all ST users. 

Atari ST BASIC to C Suggested Retail Price: $19.95 

Optional Diskette Suggested Retail Price: $14.95 



"Imagine—if someone took all of 
the BASIC commands that you 
knew and loved so well, and showed 
how those commands would look 
and work in C...in a step-by-step, 
logical sequence with lots of 
examples — wouldn't that be nice? 
Well that's exactly what Abacus had 
Mr. Hartwig do, and it's very 
effective. This book creates an 
effective bridge between ST BASIC 
and the C programming language." 

—David M. Pochron 
The Atari Journal 


Atari ST, 52GST, 1040ST, TOS, ST BASIC and ST LOGO are trademarks or registered trademarks of Atari Corp. OEM is a registered trademark of Digital Research Inc. 



































































3D Graphics 


Teaches how to create impressive, lightning-fast three-dimensional graphics 
on the Atari ST in 68000 machine language. Atari ST 3D Graphics covers 
introductory concepts and background materials, graphic animation, using 
the assembler and much more. 

Learn real-time animation with dozens of graphic routines. 3D Graphics is 
an amazing book for all programmers interested in advanced level graphics. 


Some of the topics covered include: 

• Mathematical basis for 3D graphics 

• Coordinate systems 

• Scaling the axis 

• Two- and three-dimensional 
transformations 

• Hidden lines & surfaces 

• Data structure for 3D objects 


»Object animation 

• Spatial projection 

• Rotation of objects 

• Light and shadows 

• Introduction to 3D computer-aided 
design (CAD) 


A must for all serious ST programmers. Atari ST 3D Graphics includes 
complete listings for a fascinating 3D pattern-maker and animator. 351 
pages. 

Atari ST 3D Graphics Suggested Retail Price: $24.95 

Optional Diskette Suggested Retail Price: $14.95 


ST Disk Drives: Inside and Out 

The latest title in the widely-acclaimed Abacus Atari ST Reference Library 
is the exclusive Atari ST Disk Drives: Inside and Out. This outstanding 
technical reference is Jhfi definitive source of information for the ST disk 
drives—it thoroughly discusses the floppy disk, the hard disk and RAM disk 
from both a programming and a technical perspective. In addition, the reader 
will find several full-length utilities and programming tools that enables 
him to further explore the ST disk drives’ operations and capabilities. 
Topics include: 


Information of sequential and random 

access file structures 

Access to data files from BASIC, 

Pascal, C, and FORTRAN 

Data structures and management 

The boot sector and BIOS parameter 

bloc (BPB) 

The directory and File Allocation 
Table (FAT) 


Relocation table 
Hard disk format 
Details of drive construction: 
(DMA chip, disk controller, 
connector 

layout, and organization, etc. 
Command description, status 
interpretation, floppy interface, 
hard disk partition analyzer 


ST Disk Drives: Inside and Out 
Optional Diskette 


Suggested Retail Price: $24.95 
Suggested Retail Price: $14.95 


MRIAS? 

3D GRAPHICS 
PROGRAMMING 


Concepts and Techniques 



The programs are clearly printed, 
well commented, planned in a 
sensible modular fashion, and 
contain many invaluable assembly- 
language 'tips and tricksAnd they 
work. ST programmers are fortunate 
to have this book” 

—Douglas Weir 

ST-Log 


Atari ST Disk Drives: Inside and Out is literally packed with utility 
programs. The book includes a complete listing for an easy-to-use RAM 
disk, BASIC/TOS interface, BASIC/FDC interface, BASIC loaders, Floppy- 
to-RAM disk copy, creating standard and foreign formats, and many more 
timesaving programs. Available April *87. 



Atari ST, 520ST, 1040ST, TOS, ST BASIC aixl ST LOOO are trademarks or registered trademarks of Atari Cocp. OEM is a registered trademark of Digital Research Inc. 








































PowerLedger ST 

(formerly PowerPlan ST) 

Spreadsheet/Graphics package 
for the Atari ST 

"A superior spreadsheet program for weekend 
bookeeping to the heavyweight job costing appli¬ 
cations, (Power ledger ST) is a definite winner 

—Judi Lambert 
ST World 

Ever since VisiCalc and Lotus 1-2-3 stormed the 
personal computer market, the computer has become an 
important planning tool. PowerLedger ST brings the 
power of electronic spreadsheets to the Atari ST line of 
computers—it lets the user quickly perform hundreds of 
calculations and "what-if' analyses for business 
applications, and crunch raw data into meaningful, 
comprehensible information, to keep track of budgets, 
expenses and statistics. 

PowerLedger ST is a powerful analysis package that 
features a large spreadsheet (65,536 X 65,536 
cells—over 4 billion data items). It also contains a 
built-in calculator, online notepad, and integrated 
graphics. 

PowerLedger ST is also very easy to learn, since it uses 
the familiar GEM features built into the ST. And 
PowerLedger ST can use multiple windows—up to 
seven. Data from the spreadsheet can be graphically 
summarized in in pie charts, bar graphs and line charts, 
and displayed simultaneously with the spreadsheet. For 
example, one window can display part of the 
spreadsheet; a second window a different part; and a third 
window, a pie or bar chart of the data. 

PowerLedger ST works hand-in-hand with our 
DataTrieve data management package and our TextPro 
wordprocessing package. 

PowerLedger ST’s extraordinary combination of data and 
graphic power, ease of use and low price makes it a 
perfect tool for every ST owner's financial planning 
needs. 

PowerLedger ST works with Atari ST systems with one 
or more single- or double-sided disk drives. Works with 
either monochrome or color ST monitors. Works with 
most popular dot-matrix printers (optional). 


PowerLedger 

Full-powered Spreadsheet 

37 math functions -14 dgk pracWoo 
Large size - over 4.2 bWon oeUs 
Multiple windows - up to 7 
Graphics- 7 types of graphs 



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PowerLedger ST Features: 

• Familiar drop-down menus make PowerPlan easy to 
learn and use 

• Laige capacity spreadsheet serves all the user's 
analysis needs 

• Convenient built-in notepad documents your 
important memos 

• Flexible online calculator gives you access to quick 
computations 

• Powerful options such as cut, copy and paste 
operations speeds the user'swork 

• Integrated graphics summarize hundreds of data items 

• Draws pie, bar, 3D bar, line and area charts 
automatically (7 chart types) 

• Multiple windows emphasize the user's analyses 

• Accepts information from DataTrieve, our database 
management software 

• Passes data to TextPro wordprocessing package 

• Capacities: maximum of 65,535 rows 

maximum of 65,535 columns 
variable column width 
numeric precision of 14 digits 
maximum value 1.797693 x 10^ 
minimum value 2.2 x 10~308 
37 built-in functions 

PowerLedger ST Suggested Retail Price: $79.95 


Alan ST, 520ST, 1040ST, TOS, ST BASIC and ST LOOO arc trademarks or registered trademarks of Atari Corp. 
GEM is a registered trademark of Digital Research Inc. 









































































Chartpak ST 


Professional-quality charts and graphs 
on the Atari ST 

In the past few years, Roy Wainwright has earned a 
deserved reputation as a topnotch software author. 
Chartpak ST may well be his best work yet Chartpak 
ST combines the features of his Chartpak programs for 
Commodore computers with the efficiency and power of 
GEM on the Atari ST. 

Chartpak ST is a versatile package for the ST that lets 
the user make professional quality charts and graphs 
fast. Since it takes advantage of the STs GEM 
functions, Chartpak ST combines speed and ease of use 
that was unimaginable til now. 

The user first inputs, saves and recalls his data using 
Chartpak ST's menus, then defines the data positioning, 
scaling and labels. Chartpak ST also has routines for 
standard deviation, least squares and averaging if they are 
needed. Then, with a single command, your chart is 
drawn instantly in any of 8 different formats—and the 
user can change the format or resize it immediately to 
draw a different type of chart 

In addition to direct data input, Chartpak ST interfaces 
with ST spreadsheet programs spreadsheet programs 
(such as PowerLedger ST). Artwork can be imported 
from PaintPro ST or DEGAS. Hardcopy of the finshed 
graphic can be sent most dot-matrix printers. The results 
on both screen and paper are documents of truly 
professional quality. 

Your customers will be amazed by the versatile, 
powerful graphing and charting capabilities of Chartpak 
ST. 

Chartpak ST works with Atari ST systems with one or 
more single- or double-sided disk drives. Works with 
either monochrome or color ST monitors. PWorks with 
most popular dot-matrix printers (optional). 

Chartpak ST Suggested Retail Price: $49.95 


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Selected Abacus Products for the 




DataRetrieve 

(formerly FilePro ST) 

Database management package 
for the Atari ST 


"DataRetrieve is the most versatile, and yet simple, 
data base manager available for the Atari 520ST/1040ST 
on the market to date." 

—Bruce Mittleman 
Atari Journal 

DataRetrieve is one of Abacus' best-selling software 
packages for the Atari ST computers—it's received 
highest ratings from many leading computer magazines. 
DataRetrieve is perfect for your customers who need a 
powerful, yet easy to use database system at a moderate 
price of $49.95. 

DataRetrieve's drop-down menus let the user quickly and 
easily define a file and enter information through screen 
templates. But even though it's easy to use, 
DataRetrieve is also powerful. DataRetrieve has fast 
search and sorting capabilities, a capacity of up to 
64,000 records, and allows numeric values with up to 
15 significant digits. DataRetrieve lets the user access 
data from up to four files simultaneously, indexes up to 
20 different fields per file, supports multiple files, and 
has an integral editor for complete reporting capabilities. 

DataRetrieve's screen templates are paintable for 
enhanced appearance on the screen and when printed, and 
data items may be displayed in multiple type styles and 
font sizes. 

The package includes six predefined databases for 
mailing list, record/video albums, stamp and coin 
collection, recipes, home inventory and auto 
maintenance that users can customize to their own 
requirements. The templates may be printed on Rolodex 
cards, as well as 3 x 5 and 4x5 index cards. 
DataRetrieve's built-in RAM disks support lightning- 
fast operation on the 1040ST. DataRetrieve interfaces to 
TextPro files, features easy printer control, many help 
screens, and a complete manual. 

DataRetrieve works with Atari ST systems with one or 
more single- or double-sided disk drives. Works with 
either monochrome or color monitors. Printer optional. 

Suggested Retail Price: $49.95 


DataRetrieve 

The electronic 
filing system 
for the ST 



DataRetrieve Features: 


• Easily define your files using drop-down menus 

• Design screen mask size to 5000 by 5000 pixels 

• Choose from six font sizes and six text styles 

• Add circles, boxes and lines to screen masks 

• Fast search and sort capabilities 

• Handles records up to 64,000 characters in length 

• Organize files with up to 20 indexes 

• Access up to four files simultaneously 

• Cut, past and copy data to other files 

• Change file definitions and format 

• Create subsets of files 

• Interfaces with TextPro files 

• Complete built-in reporting capabilities 

• Change setup to support virtually any printer 

• Add header, footer and page number to reports 

• Define printer masks for all reporting needs 

• Send output to screen, printer, disk or modem 

• Includes and supports RAM disk for high-speed 
1040ST operation 

• Capacities: max. 2 billion characters per file 

max. 64,000 records per file 
max. 64,000 characters per record 
max. fields: limited only by record size 
max. 32,000 text characters per field 
max. 20 index fields per file 

• Index precision: 3 to 20 characters 

• Numeric precision: to 15 digits 

• Numeric range ±10 - 308 ti ±10^ 


Atari ST, 520ST, 1040ST, IDS, ST BASIC and ST LOOO are trademarks or registered trademarks of Atari Corp. 
OEM is a registered trademark of Digital Research Inc. 


DataRetrieve 








































































TextPro 

Wordprocessing package 
for the Atari ST 

'TextPro seems to be well thought out, easy, flexible 
anf fast. The program makes excellent use of the GEM 
interface and provides lots of small enhancements to 
make your work go more easily... if you have an ST 
and haven't moved up to a GEM word processor, pick 
up this one and become a text pro." 

—John Kintz 
ANTIC 

"TextPro is the best wordprocessor available for the ST' 

—Randy McSorley 
Pacus Report 

TextPro is a first-class word processor for the Atari ST 
that boasts dozens of features for the writer. It was 
designed by three writers to incorporate features that 
they wanted in a wordprocessor—the result is a superior 
package that suits the needs of all ST owners. 

TextPro combines its "extra” features with easy 
operation, flexibility, and speed—but at a very 
reasonable price. The two-fingered typist will find 
TextPro to be a friendly, user-oriented program, with all 
the capabilities needed for fine writing and good-looking 
printouts. Textpro offers full-screen editing with mouse 
or keyboard shortcuts, as well as high-speed input, 
scrolling and editing. TextPro includes a number of easy 
to use formatting commands, fast and practical cursor 
positioning and multiple text styles. 

Two of TextPro’s advanced features are automatic table 
of contents generation and index generation 
—capabilities usually found only on wordprocessing 
packages costing hundreds of dollars. TextPro can also 
print text horizontally (normal typewriter mode) or 
vertically (sideways). For that professional newsletter 
look, TextPro can print the text in columns—up to six 
columns per page in sideways mode. 

The user can write form letters using the convenient 
Mail Merge option. TextPro also supports GEM- 
oriented fonts and type styles—text can be bold, 
underlined , italic , superscript^ ouLtdldimedU etc., and in a 
number of point sizes. TextPro even has advanced 
features for the programmer for development with its 
Non-document and C-sourcecode modes. 

TextPro Suggested Retail Price: $49.95 



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He have an extensive lineup of 
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TextPro ST Features: 

• Full screen editing with either mouse or keyboard 

• Automatic index generation 

• Automatic table of contents generation 

• Up to 30 user-defined function keys, max. 160 
characters per key 

• Lines up to 180 characters using horizontal scrolling 

• Automatic hyphenation 

• Automatic wordwrap 

• Variable number of tab stops 

• Multiple-column output (maximum 5 columns) 

• Sideways printing on Epson FX and compatibles 

• Performs mail merge and document chaining 

• Flexible and adaptable printer driver 

• Supports RS-232 file transfer (computer-to-computer 
transfer possible) 

• Detailed 65+ page manual 

TextPro works with Atari ST systems with one or more 
single- or double-sided disk drives. Works with either 
monochrome or color ST monitors. 

TexPro allows for flexible printer configurations with 
most popular dot-matrix printers. 


Anri ST, 520ST, 1040ST, TOS, ST BASIC and ST LOOO are trademarks or registered trademarks of Atari Corp. 
OEM is a registered trademark of Digital Research Inc. 



















































Selected Abacus Products for the 




PaintPro 

Design and graphics software for the ST 

PaintPro is a very friendly and very powerful package 
for drawing and design on the Atari ST computers that 
has many features other ST graphic programs don't 
have. Based on GEM™, PaintPro supports up to three 
active windows in all three resolutions—up to 640x400 
or 640x800 (full page) on monochrome monitor, and 
320 x 200 or 320 x 400 on a color monitor. 

PaintPro's complete toolkit of functions includes text, 
fonts, brushes, spraypaint, pattern fills, boxes, circles 
and ellipses, copy, paste and zoom and others. Text can 
be typed in one of four directions—even upside down— 
and in one of six GEM fonts and eight sizes. PaintPro 
can even load pictures from "foreign" formats (ST 
LOGO, DEGAS, Neochrome and Doodle) for 
enhancement using PaintPro's double-sized picture 
format. Hardcopy can be sent to most popular dot¬ 
matrix printers. 

PaintPro Features : 

• Wo±s in all 3 resolutions (mono, low and medium) 

• Four character modes (replace, transparent, inverse 
XOR) 

• Four line thicknesses and user-definable line pattern 

• Uses all standard ST fill patterns and user definable 
fill patterns 

• Max. three windows (dependng on available memory) 

• Resolution to 640 x400 or 640x800 pixels 
(mono version only) 

• Up to six GDOS type fonts, in 8-, 9-, 10-, 14-, 16-, 
18-, 24- and 36-point sizes 

• Text can be printed in four directions 

• Handles other GDOS compatible fonts, such as those 
in PaintPro Library # 1 

• Blocks can be cut and pasted; mirrored horizontally 
and vertically; marked, saved in LOGO format, and 
recalled in LOGO 

• Accepts ST LOGO, DEGAS, Doodle & Neochrome 
graphics 

• Features help menus, full-screen display, and UNDO 
using the right mouse button 

• Most dot-matrix printers can be easily adapted 

PaintPro works with Atari ST systems with one or 
more single- or double-sided disk drives. Works with 
either monochrome or color ST monitors. Printer 
optional. 

PaintPro Suggested Retail Price: $49.95 


PaintPro 



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AUri ST, 520ST, 1040ST, TOS, ST BASIC and ST LOGO arc trademarks or registered trademarks of Atari Corp. 
GEM is a registered trademark of Digital Research Inc. 















































































































































Selected Abacus Products for the 


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PaintPro Library #1 


Fonts and Clipart for the Atari ST 

The STs excellent graphics capability make it a natural 
for computer art and design. To add even more 
flexibility and features to PaintPro we've released 
PaintPro Library #1, a companion graphics package that 
contains a diverse range of fonts and symbols for almost 
every application. It contains five new original fonts for 
the ST: Swiss, Computer, Chantal, Mixed and Thames. 
Paint Pro Library #1 also contains scores of new 
symbols, borders and ornamental lines. As you can see 
from the examples in the next column, this program 
fills a real need for your customers' design requirements. 


PaintPro Library #1 contains five new specially 
designed fonts: 


• Swiss 

• Computer 

• Chantal 

• Mixed 

• Thames (Old English) 


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Also included in PaintPro Library #1: 

• Over 50 drafting symbols “$— 

• Over 100 electronic symbols 

• Over 100 clip art symbols —g 

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All fonts are GDOS compatible and may be used with 
"foreign" software that supports the GDOS. PaintPro 
Library #1 also has hundreds of symbols, borders, and 
ornamental lines for use in your graphic designs. These 
libraries are DEGAS® compatible. 

PaintPro Library #1 Suggested retail price: $29.95 


Over 50 drafting symbols 

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Anri ST, 520ST, 1040ST, TOS, ST BASIC and ST LOGO are trademarks or registered trademarks of Atari Corp. 
OEM is a registered trademark of Digital Research Inc. 






































How to Order 




Abacus mm P.0. Box 7219, Grand Rapids, Ml 49510 


All of our ST products—applications and language 
software, and our acclaimed 14 volume Atari ST Reference 
Library —are available at more than 2000 dealers in the U.S. 
and Canada. To fmd out the location of the Abacus dealer 
nearest to you, call: 


(616) 241-5510 

8:30 am-8:00 pm Eastern Standard Time 

Or order from Abacus directly by phone with your credit 
card. We accept Mastercard, Visa and American Express. 

Every one of our software packages is backed by the 
Abacus 30-Day Guarantee —if for any reason you're not 
satisfied by the software purchased directly from us, simply 
return the product for a full refund of the purchase price. 

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Shipping/Handling charge 
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Check/Money order TOTAL enclosed 

4.00 


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The Atari ST is a "user-friendly" computer. With its icon-based operating 
system, the ST is ideal for a beginner, although many aspects of the ST 
can be confusing to the first-time computer user. The Atari ST for 
Beginners will help you learn the essentials of the Atari ST without 
problems. Some of the topics in this informative book include: 

• Setup and connection 

• TOS, GEM and application programs 

• Introductions to BASIC and LOGO programming 

• BASIC program listings with detailed explanations 

• Glossary of computer terms 

• A short history of computer science 

• What else you can do with your Atari ST—now and in the future 
About the authors: 

Rainer Luers is a noted teacher of computer science and author. Michael 
Stein, one of the chief editors of the West German magazine Data Welt, 
has applied his computer knowledge and his humorous and informal 
writing style to this book, making the ST easy for everyone to understand. 


ISBN □- c ilb43^-SS-D 


The ATARI logo and ATARI ST are trademarks of Atari Corp. 


Part of the continuing series of informative books from 



A Data Becker Book